Yellow Glass Research Articles

Chicxulub Crater, Yucatan: Tektites, impact glasses, and the geochemistry of target rocks and breccias

A comparison of breccias and basement rocks from four drill holes near the Chicxulub impact structure, Yucatan (a possible Cretaceous-Tertiary [K-T] boundary crater), with black and yellow impact glasses from the Haitian K-T boundary layer shows that mixtures of andesite-like rocks with carbonates and evaporites from Chicxulub are compositionally different from the yellow glasses. At the time of impact, the Chicxulub area was covered by evaporitic and carbonate deposits several kilometres thick. Because impact glasses are generally produced by shock melting of surface rocks, a link between the Haitian glasses and Chicxulub is difficult to understand. The δ 34 S isotopic signature of Chicxulub breccias and evaporites is incompatible with that of a continental K-T boundary. We suggest that the pre-impact target stratigraphy at Chicxulub as well as the interpretation of the carbonate-evaporite rocks as breccias should be revised.

Geochemistry of impact glasses from the K/T boundary in Haiti: Relation to smectites and a new type of glass

We have individually analyzed twelve black and seven yellow glasses from the K/T boundary section at Beloc, Haiti, plus three smectite mantles around black glasses. The main chemical differences between black and yellow glasses are higher S, Ca, Mg, Zn, As, Br, Sb, and Au, but lower K, Na, and Si abundances in the yellow glasses. We have found high-CaO yellow glasses with low S contents (0.08, 0.17 wt% ), which may be explained by fusion of carbonate-rich sediments. Microprobe studies of individual glasses show that the black glasses are very homogeneous in their composition at the 10–100 μm level, while yellow glasses show much more variability and different intra-sample elemental correlations. One of the black glasses has higher SiO 2 and K 2O abundances, but lower concentrations of all other major elements. This suggests the existence of a third glass type, which we have named the high Si-K variety (HSi,K glass). The glass shows areas consisting of pure SiO 2 (maybe lechatelierite) and some schlieren with lower SiO 2 content. The chemical composition indicates that the HSi,K glass may have originated from melting of a sedimentary source rock, such as shale or argillite. Severe changes in major and trace element composition occur during alteration of the glass, as documented by analyses of adhering smectites. The REE patterns in the glass are similar to average upper crust, but the smectites exhibit much lower abundances and flat patterns, not unlike the patterns observed in claystones at numerous K/T boundary sites. The suggestion that the Chicxulub structure in Yucatan may be the source crater for the K/T impact glasses is not fully supported by the currently available data. Impact glasses and tektites are produced from the surface layers of their targets. At Chicxulub, the target stratigraphy comprised mainly carbonates and evaporites. Although we cannot exclude Chicxulub as a source, the present data do not provide any firm chemical evidence for a connection. We conclude, however, that the Haiti glasses have formed by impact and have later undergone alteration by low-temperature hydrothermal processes to produce clays. The boundary claystones at K/T boundary sites may very well be alteration products of these impact glasses.

Mineralogy and petrology of the Haiti Cretaceous/Tertiary section

The Cretaceous/Tertiary sections in Haiti consist of a sequence of graded beds of turbidity current or gravity flow origin. Each section may consist variously of five major constituents: (1) black glass, (2) brown globules, veinlets and blobs, (3) argillaceous limestone clasts, (4) white clasts and shards, and (5) a fine-grained matrix rich in smectite, zeolites and calcite. In addition, there are trace amounts of a high-calcium yellow glass. The black glass particles are vesicular, apparently unaltered with an andesitic to dacitic composition, and in sharp contact with the secondary matrix and veinlet alteration products. The brown globules, veinlets and blobs consist of a palagonite-smectite mix of a distinctly different composition than the black glasses. White clasts and shards of a still different (more hydrated) composition are also present. All of these materials are sometimes associated with accretionary lapilli(?). The hydration or alteration products—brown globules, white clasts and shards, and matrix—amount to something in excess of 95% of the total deposits. The sedimentology, mineralogy and petrology of the Haiti sections has provided a record of a sequence of probable volcanic events.

Geochemical constraints on source region of Cretaceous/Tertiary impact glasses

THE 50-cm-thick Cretaceous/Tertiary boundary layer at Beloc in Haiti contains spherules of silicic black glass, 1–8 mm in diameter, which have been attributed to impact fusion of continental crust1. Calcic yellow glass (up to 30 wt% CaO) forms a coating on and streaks within some black glass spherules, and has been attributed to melting of carbonate-rich sediment1, or organic-rich or pyritic limestone2. Here we present new trace-element and stable and radiogenic isotope data which show that the silicic glass is derived from continental crust of andesitic composition, whereas the high-Ca glass formed by melting of evaporite-rich sediment. This is confirmed by melting experiments with evaporite and andesite at 1,200–1,400 °C, which approximately reproduce the high-Ca glass. The temperature-dependent variation of sulphur content in synthetic high-Ca glasses indicates a formation temperature of 1,300 °C for the Haiti glasses. The geology of the impact site inferred from the geochemistry of the Haiti glasses matches the lithologies found in the 180-km Chicxulub structure, which occurs in Cretaceous evaporite deposits in Mexico. The high sulphur content of the calcic glasses suggests that the impact may have generated significant emissions of sulphur dioxide to the atmosphere, causing short-term global cooling.

Effects of yellow, orange and red filter glasses on the thresholds of a dark‐adapted human eye

Effects of 13 different yellow, orange and red (Schott) longpass filter glasses on the extrafoveal thresholds obtained by 3 normal subjects after dark-adaptation were measured using a Goldman-Weekers adaptometer. When filters GG400, GG420, GG435, GG455, GG475, GG495, OG515 and OG530 (cutting off radiation up to 527 nm) were used there was no significant change in the threshold value. However, significantly higher threshold values were obtained with the use of the filters OG550, OG570, OG590, RG610 and RG630.

Ion microprobe studies of trace elements in Apollo 14 volcanic glass beads: Comparisons to Apollo 14 mare basalts and petrogenesis of picritic magmas

The major element geochemistry of picritic lunar glass beads indicates that they represent primary basaltic liquid compositions and, as such, provide unique information concerning the origin of mare basalts and characteristics of the lunar interior. This study used ion microprobe techniques for trace element analysis of individual glass beads representing seven compositionally distinct types of picritic glass beads from the Apollo 14 site [high-Ti glasses (17–11% TiO 2): Red/Black, Orange; intermediate-Ti glasses (5–4% TiO 2): Yellow; low-Ti glasses (2.8% TiO 2): LAP (low alkali, picritic; Papike et al., 1989); very low-Ti glasses (<1% TiO 2): Green A, VLT, Green B]. The Green B, Green A, VLT, and LAP glasses are typically LREE enriched. The total REE abundance of Green A, VLT, and LAP overlap (Ce = 30 to 80 × chondrite) whereas the REE abundances of the more MgO-rich Green B are substantially lower (Ce = 8 to 18 × chondrite). The trace element signature [REE patterns and abundances, ( Ba Sr ) > 1 ] of these glasses are different from low-Ti mare basalts at other sites but are similar to crystalline basalts at the Apollo 14 site. The intermediate to high-Ti picritic glasses exhibit a flat to slightly positive LREE slope and a negative HREE slope. The Orange glass has a higher total REE abundance and a slightly larger negative Eu anomaly than the Red/Black and Yellow glasses. Relative to the Apollo 17 high-Ti glasses, Apollo 14 high-Ti glasses are enriched in REE, LREE/HREE, Y, V, Zr, Sr, Ba, and Ba Sr and are similar in alkali elements (Li, Rb), Co, and Sc. Trace element modeling, within the context of liquid lines of descent and major element characteristics, indicates that the picritic glass beads at the A-14 site are not related by low pressure fractional crystallization to each other or to crystalline basalts at the Apollo 14 or other landing sites. A possible exception is the relationship between LAP and basalts of the high-Al basalt suite. The wide range of primary magma compositions and the lack of petrogenetic linkage (via crystal fractionation) to crystalline basalts indicates that either a wide compositional range of evolved mare basalts has not yet been sampled or a unique mechanism is selectively tapping these picritic magmas directly from their mantle source region. The wide range of major and trace element characteristics of the volcanic glass beads is consistent with derivation from mineralogically distinct sources which consist of varying proportions of olivine + orthopyroxene ± clinopyroxene ± ilmenite ± plagioclase ± KREEP component. The evolved KREEP component may have been incorporated into these primary picritic magmas by either assimilation-fractional crystallization-type processes (AFC) or by hybridization of the mantle source. The former appears less likely due to the general systematic increase in incompatible elements relative to Ti concentration and the apparent lack of crystallization that is required in AFC-type models. The hybridization processes may be the result of “sinker” mechanisms as proposed by Ringwood and Kesson (1976), a manifestation of original mantle inhomogeneities, or a magma ocean stirred by large impacts.

Growth and Production of Yellow Eels and Glass Eels in Ponds

AbstractTwo experiments (I and II) were performed in drainable ponds. Yellow eels Anguilla anguilla (L.) were stocked in early June at three biomasses: 10, 20 and 60 kg · ha−1 in experiment I; and 10, 20 and 40 kg · ha−1 in experiment II. The mean body weights were 27.0 and 24.2 g respectively. Glass eels were stocked only in experiment II at equal densities of 1600·ha−1. In both experiments each biomass of yellow eel was combined in a factorial design with three cyprinid communities differing in biomass and in species‐ and size‐composition. The ponds were drained in autumn. The final body weights at draining ranged from 25.9 to 63.6 g for yellow eel and from 3.9 to 8.8 g for glass eel. The final body weights of yellow eel and of glass eel decreased with increasing biomass of yellow eel. No significant relation was found between the bream Abramis brama (L.) biomass and the growth of eel. The growth rates of yellow eel and glass eel were positively correlated in experiment II. At higher biomasses of yellow eel the percentage females decreased slightly. The recapture rates of yellow eel in experiments I and II amounted to 69.4 ± 9.8 % and 92.2 ± 4.9% (mean ± sd) respectively. The lower recapture rates in experiment I were caused by the inappropriate draining technique used. The glass eels were recaptured with 75.0·5.6% efficiency. The maximum net production of yellow eel occurred at a biomass of 20–40kg·ha−1 and amounted to 19 kg·ha−1.

Della Makes Life

He was embarrassed when he saw her coming toward him. He wished he could have just disappeared into the crowd and kept going as far away from Norman Manley Airport as was possible. Della returning, Della come back from New York after a whole year. Della dressed in some clothes which make her look like a checker cab. What in God's name was a big forty-odd-year-old woman who was fat when she leave Jamaica, and get worse fat since she go to America, what was this woman doing dressed like this? Della was wearing a stretch-to-fit black pants, over that she had on a big yellow and black checked blouse, on her feet was a pair of yellow booties, in her hand was a big yellow handbag, and she had on a pair of yellow framed glasses. See ya Jesus! Della no done yet, she had dyed her hair with red oxide and Gerri Curls it till it shine like it grease and spray. Oh Della what happen to you? Joseph never even bother take in her anklet and her big bracelets and her gold chain with a pendant, big as a name plate on a lawyer's office, marked Material Girl. Joseph could sense the change in Della through her letters. When she just went to New York, she used to write him D. V. every week.

Room Temperature Excitonic Absorption in Small Cds Crystallites

AbstractThe absorption characteristics of commercial CdS-containing yellow glass which shows constant transmitted intensity over a range of incident CW laser intensity have been studied at room temperature. Although the thick specimen (t&gt;0.6 mm) shows only a broad step-like feature near λ&gt;460 nm, a thin (t-0.09 mm) specimen shows two absorption features which can be interpreted as the first two quantum-confined exciton absorption features corresponding to a crystallite size of -45 Å. The absorption spectrum of a sample (t∼O.6 mm) heated for 15 min. at 700°C shows two new absorption features at 450 nm and 380 nm, which correspond to a much smaller crystallite size of -25 Å. This reduction in size is not inconsistent with estimates made from a well-known model for crystallite growth. Some consequences of these changes in the absorption features on the optical nonlinearities of the glass will be discussed.

Quenching and disruption of lunar KREEP lava flows by impacts

The Apollo 15 KREEP basalts—so called because they are rich in trace elements such as potassium, rare-earth elements and phosphorus—are thought to be volcanic rocks1, based on their petrographic characteristics, chemical variations and geological context2. The lavas were extruded ∼3.85 Gyr ago3, and most are represented by only tiny fragments (nearly all less than 1 cm across). Here I report the results of a re-examination of their petrography. Several of them contain yellow residual glasses which cross-cut the crystallized phases; some show more extreme disruption. The features of the glasses appear to be compatible only with impact disruption, ejection and quenching from actively crystallizing flows, indicating a high impact flux immediately after the impact that formed the Imbrium basin. No other example of impacts into active lava flows is known in the Solar System.

Effects of Yellow Filter Glasses on the Results of Photopic and Scotopic Photometry

I measured the luminosity of a white surface with seven different yellow filter glasses and a photometer with two different sensitivities, which resembled the photopic and scotopic sensitivity of a Commission Internationale d'Eclairage standard observer. When measured with filters GG 400, GG 420, GG 435, and GG 455, there was a small and almost equal reduction in the relative photopic and scotopic luminosities. Measured with filters GG 475, GG 495, and OG 515, there was a more marked reduction in the scotopic luminosities than in the photopic luminosities.

Effects of yellow filter glasses on colour discrimination of normal observers and on the illumination level.

Ten healthy young persons wearing yellow filter glasses were examined with the Farnsworth-Munsell 100-hue test using a Macbeth daylight illuminator. Results obtained with (Schott) filters GG 400, GG 420, GG 435 and GG 455 were within normal limits. Using filters GG 475, GG 495 and OG 515 the mean total error score was 123.9, 203.8 and 226.9, respectively, and the test diagram showed a tritan error axis. Illumination of the Macbeth daylight illuminator measured without filters was 1800 lux. Using yellow filters the illumination varied from 1650 to 1500 lux.

Origin of lead from green glass of Apollo 15426: A search for primitive lunar lead

A major obstacle in lunar U‐Pb chronology is the elusiveness of the primary Pb isotopic composition and U/Pb ratio and therefore the Pb evolution for the early history of the moon. In an attempt to seek the primitive lunar Pb isotopic composition, green glass from lunar clod 15426,49 was studied for U‐Th‐Pb systematics because it is extremely Mg‐rich and known to be the most primitive among sampled lunar volcanic rocks. Green glass and yellow impact glass were handpicked, washed with water, then washed in an acid mixture (0.3 N HBr + 0.2 N HF), and the washes and residues were analyzed. In contrast to the Pb from Apollo 17 orange glass, Pb from the surface of the green glass spherules is totally different from that of the spherule interior, but is similar to lunar surface lead. Data for the interior Pb yield a 207Pb/206Pb age of 3.41 Ga. Because of the low Pb concentration and high U/Pb ratio observed for the interior, the initial Pb was poorly defined. Nevertheless, the data indicate that lunar Pb evolved in an environment with 238U/204Pb = 19–55, which is considerably lower than those for mare basalts (around 300) but higher than values for the earth (6–8).

Remote sensing of lunar pyroclastic mantling deposits

Mantling deposits on the Moon are considered to be pyroclastic units emplaced on the lunar surface as a result of explosive fire fountaining. These pyroclastic units are characterized as having low albedos, having smooth fine-textured surfaces, and consisting in part of homogeneous, Febearing volcanic glass and partially crystallized spheres. Mantling units exhibit low returns on depolarized 3.8-cm radar maps, indicating an absence of surface scatterers in the 1- to 50-cm-size range. A number of reflectance spectra from several regional pyroclastic deposits are presented for the first time; these data support a previous interpretation that mantling units have a unique spectral signature which is indicative of the presence of a significant Fe-bearing volcanic glass component. The Rima Bode region is discussed as an example of an area in which several types of remote sensing data (including 3.8-cm radar, spectral reflectance, and multispectral vidicon data) were used to reconstruct the geologic events surrounding the emplacement of a regional pyroclastic mantling deposit. The recognition of numerous varieties of volcanic glass samples, especially relatively high-albedo (e.g., green, yellow) glasses, suggests the existence of additional, unrecognized mantling deposits with albedos higher than those studied to date. On the basis of the remote sensing data summarized and presented, five new areas have been identified which may represent higher-albedo regional pyroclastic deposits.

History of the Apollo 15 yellow impact glass and sample 15426 and 15427

Individual pieces of the Apollo 15 yellow impact glass from 15426 and 15427 were studied using the laser microprobe to determine their 39Ar‐40Ar age and their 38Ar‐37Ar exposure age. Except for the extractions from one fragment, the age determinations required significant correction for trapped 40Ar. Data from multiple extractions on each fragment were used to make individual 40Ar/36Arsw versus 39ArK/36Arsw plots from which the apparent age and trapped component for each fragment was determined. An age of 3.35±0.05 AE was determined for the age of the impact event that formed these glasses. This age cannot be reconciled with the age prediction of Delano et al. [1982]. Since these glasses were probably produced by an impact into a target of moderate‐TiO2 basalts, and the only known moderate‐TiO2 basaltic flows are younger than the impact event [Boyce and Johnson, 1978], the target for these glasses must be covered up by later basaltic flows. The average 38Ar‐37Ar exposure age for these glasses was 274±74 m.y. Other glasses from clods 15426 and 15427 give similar exposure ages [Spangler et al. 1984]. Two possible reasons for this similarity is that (1) the clods formed at greater than 300 m.y. ago so that all glasses in 15426 and 15427 shared a common exposure history, and (2) the gardening at Station 7 produced a soil with an average exposure age of ∼300 m.y.

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

The Apollo 15 yellow impact glasses are characterized by moderate TiO2 (∼ 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 basalts were the youngest lava flows known to exist on the moon (i.e., Eratosthenian‐age lavas in Oceanus Procellarum and Mare Imbrium). Specific tests are proposed for evaluating this provocative hypothesis.

Pyrotechnie reaction of boron and lead monoxide: heats of reaction and differential scanning calorimetry studies

Differential scanning calorimetry (DSC) has been applied to the study of the fast reaction of boron with lead monoxide, and bomb calorimetry has been utilized to compare experimental and theoretical heats of reaction. DSC traces were obtained for PbO/B compositions (80/20, 50/50 and 97/3 wt%) and also for PbO/B 20 3 (1:1) mixtures, utilizing scan rates of 5, 10 and 20 ° min −1 and conducting the measurements under an atmosphere of argon (20ml min −1). Two well-defined exothermic peaks were obtained in the DSC traces and analysis of the data, together with examination of infra-red spectra, indicated the presence of B 20 3 and Pb in the reaction products. The excess heat outputs, at PbO levels above the stoichiometric level, are explained by the exothermic reaction of PbO with B 20 3 to form clear, slightly yellow glasses. The formation of a surface-coating of B 2O 3 on the boron particles has an important effect on the rate of the main PbO-B reaction.

Control of excitation in the fluorescence microscope

In fluorescence microscopy image brightness and contrast and the rate of fading depend upon the intensity of illumination of the specimen. An iris diaphragm or neutral density filters may be used to reduce fluorescence excitation. Also the excitation band-width may be varied by using a broad band exciter filter with a set of interchangeable yellow glass filters at the lamphouse.

On Dostoevsky's Poetics and Archaic Patterns of Mythological Thought

and premeditated city in the whole wide (Notes from Underground, Pt. I, ch. 1); St. Petersburg there are some strange little corners ... it is as though a completely different life is led in these corners ... a life which might occur in nevernever land, but not here ... this life is a mixture of something quite fantastic, of ardent ideals, and, at the same time ... colorlessly prosaic and ordinary, not to say, impossibly vulgar Second Night, White Nights); But in passing, however, I must observe that I consider the Petersburg morning, which one would think the most prosaic in the whole earthly sphere, to be virtually the most fantastic in the world ... A hundred times amid these mists I have been overcome by a strange but persistent dream: that when this mist disperses and rises, the whole decayed and dank city will go with it, rising in the mist and disappearing like smoke (The Raw Youth and elsewhere). Fantastic (and words of the same root) can be found in Crime and Punishment around thirty times. most characteristic use is in reference to Raskolnikov: How fantastic he is ... he has a fantastic heart ... I like you for your fantastical qualities ... the matter will finish differently, in afantastic way, etc. 10 Compare from the old woman's house (the first visit); after the dream on Petrovsky island; when leaving the yard where the stolen goods are hidden, into the street in the direction of the square; when leaving home after Luzhin's visit; after Marmeladov's death; after the second visit to Porfiry; and finally, the actual rebirth, which takes place at an extreme distance from home. And on the other hand, suffering usually reaches its zenith inside the house. 11 See 'What a nasty room you have, Rodya, just like a coffin ... I'm sure it's partly the room that's made you so melancholy' . . . 'The room? Yes, the room is responsible for a great deal ... I've thought so, too.' 12 For a linguistic codification of the image, see The proximity of Sennaya ... the inhabitants crowded into these streets and alleys in the middle of St. Petersburg. tendency to stay in the middle of the room is observed and frequently associated with passive perceptions (hearing, seeing), with the involuntary surfacing of bad or generally negative thoughts. See was standing meditatively in the middle of the room. A dark and tormenting thought came to him ... He stood in the middle of the room and was looking round with tortured bewilderment. See also the moments of oblivion and depression in connection with the middle of the bridge; critical moments (the middle of the room-Sonya, Lizaveta, etc.). In contrast, walking around the room (for example, This content downloaded from 207.46.13.131 on Sun, 16 Oct 2016 05:14:27 UTC All use subject to http://about.jstor.org/terms ON DOSTOEVSKY'S POETICS 349 from the door or stove to the window, or from corner to corner) is most frequently linked with the active principle-thoughts, emotions (particularly agitation), etc., preparing for subsequent action. Cf. the behavior of Dunya, Katerina Ivanovna, Porfiry (he customarily runs, spins, and even, in the course of the artisan's evidence, skips), Lebezyatnikov, Amalia Ivanovna, etc. 13 Only a few examples will be indicated here. Cf. Raskolnikov's first dream: There was always such a crowd there, they bawled so much, laughed, swore so crudely and sang hoarsely . . . fought . . . it becomes very noisy . . . they come out shouting and singing ... there's laughter in the crowd . . . they all clamber into Mikolka's cart with laughing and joking . .. the crowd is also laughing, and indeed, how could they help it ... the laughter in the cart and in the crowd redoubles, etc. 14 Consider, for example, the yellow of the wallpaper at the old woman's place (also the yellow furniture, the yellow frames), Porfiry's yellow furniture, the yellow water in the yellow glass at the police station, the pale yellow faces of Raskolnikov and Katerina

The Binary Oxide System TeO2MoO3

AbstractPhase analysis of the mixed oxide system TeO2MoO3 by means of x‐ray diffraction and optical microscopy indicates the formation of a new phase, α‐Te2MoO7, stable at room temperature. Below 500°C mixtures of crystalline products are obtained or complete devitrification can easily be induced in the system TeO2MoO3. Above this temperature, tendency to glass formation is observed under the conditions employed, due to the liquidus temperature effect. Quenching of a melt of Te2MoO7 yields a dark yellow glass, α‐Te2MoO7. X‐ray and density measurements were used to explore the range of stoichiometry and exclude formation of solid solutions in the system; no apparent relationship exists between the crystal structures of the component oxides and the binary compound.