bluuebunny/crossref_metadata_2025 huggingface dataset:
Special Issue: “Scholarly Editing in the Twenty‐first Century”– Introduction
Authors: Marotti Arthur F.
Published: February 2010

This piece is the introduction to the Literature Compass special issue on ‘Scholarly Editing in the Twenty‐First Century’.

The special issue is made up of the following pieces:

‘Special Issue: “Scholarly Editing in the Twenty‐First Century”– Preface’, Regenia Gagnier, Literature Compass 7.2 (2010): 33–34, doi: 10.1111/j.1741‐4113.2009.00672.x.

‘Special Issue: “Scholarly Editing in the Twenty‐First Century”– Introduction’, Arthur F. Marotti, Literature Compass 7.2 (2010): 35–36, doi: 10.1111/j.1741‐4113.2009.00673.x.

‘Electronic Archives and Critical Editing’, Jerome McGann, Literature Compass 7.2 (2010): 37–42, doi: 10.1111/j.1741‐4113.2009.00674.x.

‘Theorizing the Digital Scholarly Edition’, Hans Walter Gabler, Literature Compass 7.2 (2010): 43–56, doi: 10.1111/j.1741‐4113.2009.00675.x.

‘Editing Without Walls’, Peter Robinson, Literature Compass 7.2 (2010): 57–61, doi: 10.1111/j.1741‐4113.2009.00676.x.

‘Our Affection for Books’, Susan J. Wolfson, Literature Compass 7.2 (2010): 62–71, doi: 10.1111/j.1741‐4113.2009.00677.x.

‘His Days Among the Dead Are No Longer Passed: Editing Robert Southey’, Lynda Pratt, Literature Compass 7.2 (2010): 72–81, doi: 10.1111/j.1741‐4113.2009.00678.x.

‘Different Demands, Different Priorities: Electronic and Print Editions’, Stuart Curran, Literature Compass 7.2 (2010): 82–88, doi: 10.1111/j.1741‐4113.2009.00679.x.

‘Editing Manuscripts in Print and Digital Forms’, Arthur F. Marotti, Literature Compass 7.2 (2010): 89–94, doi: 10.1111/j.1741‐4113.2009.00680.x.

‘All of the Above: The Importance of Multiple Editions of Renaissance Manuscripts’, Steven W. May, Literature Compass 7.2 (2010): 95–101, doi: 10.1111/j.1741‐4113.2009.00681.x.

‘Editing Early Modern Women’s Manuscripts: Theory, Electronic Editions, and the Accidental Copy‐Text’, Margaret J.M. Ezell, Literature Compass 7.2 (2010): 102–109, doi: 10.1111/j.1741‐4113.2009.00682.x.

‘Different Strokes, Same Folk: Designing the Multi‐form Digital Edition’, Daniel Paul O’Donnell, Literature Compass 7.2 (2010): 110–119, doi: 10.1111/j.1741‐4113.2009.00683.x.

‘Special Issue: “Scholarly Editing in the Twenty‐First Century”– A Conclusion’, Laura Mandell, Literature Compass 7.2 (2010): 120–133, doi: 10.1111/j.1741‐4113.2009.00684.x.

‘Special Issue: “Scholarly Editing in the Twenty‐First Century”– Combined Bibliography’, Marotti et al., Literature Compass 7.2 (2010): 134–144, doi: 10.1111/j.1741‐4113.2009.00685.x.
Different Demands, Different Priorities: Electronic and Print Editions
Authors: Curran Stuart
Published: February 2010

This article is part of a Literature Compass special issue on ‘Scholarly Editing in the Twenty‐First Century’.

The special issue is made up of the following pieces:

‘Special Issue: “Scholarly Editing in the Twenty‐First Century”– Preface’, Regenia Gagnier, Literature Compass 7.2 (2010): 33–34, doi: 10.1111/j.1741‐4113.2009.00672.x.

‘Special Issue: “Scholarly Editing in the Twenty‐First Century”– Introduction’, Arthur F. Marotti, Literature Compass 7.2 (2010): 35–36, doi: 10.1111/j.1741‐4113.2009.00673.x.

‘Electronic Archives and Critical Editing’, Jerome McGann, Literature Compass 7.2 (2010): 37–42, doi: 10.1111/j.1741‐4113.2009.00674.x.

‘Theorizing the Digital Scholarly Edition’, Hans Walter Gabler, Literature Compass 7.2 (2010): 43–56, doi: 10.1111/j.1741‐4113.2009.00675.x.

‘Editing Without Walls’, Peter Robinson, Literature Compass 7.2 (2010): 57–61, doi: 10.1111/j.1741‐4113.2009.00676.x.

‘Our Affection for Books’, Susan J. Wolfson, Literature Compass 7.2 (2010): 62–71, doi: 10.1111/j.1741‐4113.2009.00677.x.

‘His Days Among the Dead Are No Longer Passed: Editing Robert Southey’, Lynda Pratt, Literature Compass 7.2 (2010): 72–81, doi: 10.1111/j.1741‐4113.2009.00678.x.

‘Different Demands, Different Priorities: Electronic and Print Editions’, Stuart Curran, Literature Compass 7.2 (2010): 82–88, doi: 10.1111/j.1741‐4113.2009.00679.x.

‘Editing Manuscripts in Print and Digital Forms’, Arthur F. Marotti, Literature Compass 7.2 (2010): 89–94, doi: 10.1111/j.1741‐4113.2009.00680.x.

‘All of the Above: The Importance of Multiple Editions of Renaissance Manuscripts’, Steven W. May, Literature Compass 7.2 (2010): 95–101, doi: 10.1111/j.1741‐4113.2009.00681.x.

‘Editing Early Modern Women’s Manuscripts: Theory, Electronic Editions, and the Accidental Copy‐Text’, Margaret J.M. Ezell, Literature Compass 7.2 (2010): 102–109, doi: 10.1111/j.1741‐4113.2009.00682.x.

‘Different Strokes, Same Folk: Designing the Multi‐form Digital Edition’, Daniel Paul O’Donnell, Literature Compass 7.2 (2010): 110–119, doi: 10.1111/j.1741‐4113.2009.00683.x.

‘Special Issue: “Scholarly Editing in the Twenty‐First Century”– A Conclusion’, Laura Mandell, Literature Compass 7.2 (2010): 120–133, doi: 10.1111/j.1741‐4113.2009.00684.x.

‘Special Issue: “Scholarly Editing in the Twenty‐First Century”– Combined Bibliography’, Marotti et al., Literature Compass 7.2 (2010): 134–144, doi: 10.1111/j.1741‐4113.2009.00685.x.
Verbal dyspnoea score predicts emergency department departure status in patients with shortness of breath
Authors: Saracino Amanda , Weiland Tracey J , Jolly Brian , Dent Andrew W
Published: February 2010

Objectives:  We examined whether a previously validated verbal dyspnoea rating scale, and/or other demographic and clinical parameters, could predict ED departure status, among ED patients presenting with shortness of breath.

Methods:  In this prospective observational study, a convenience sample of patients presenting to an inner urban adult tertiary hospital ED with shortness of breath were assessed at triage using objective and subjective breathlessness parameters. These included respiratory rate, oxygen saturation, heart rate, systolic blood pressure and verbal dyspnoea scores. A verbal dyspnoea score for worst dyspnoea during the current episode and basic demographic and presentation characteristics were also collected. These variables were assessed as predictors of ED departure status (inpatient admission or ED discharge) using logistic regression.

Results:  From a sample of 253 participants, verbal dyspnoea scores ≥8 predicted inpatient admission 89% specificity (95% confidence interval [CI] 82.1–93.4), and scores ≤3 predicted discharge with 95% specificity (95% CI 89.5–98.0). For patients with shortness of breath as the primary complaint, the combination of verbal dyspnoea score ≥6, heart rate ≥94 bpm at triage and ambulance arrival predicted admission with 90% sensitivity (95% CI 82–95%) and 84% specificity (95% CI 73–92%). These same variables predicted admission for all patients with 84% sensitivity (95% CI 75.8–89.2) and 79% specificity (95% CI 71.5–85.5).

Conclusion:  Verbal dyspnoea score, alone and in combination with heart rate and arrival transport, can accurately predict admission. Once validated they might be useful in assessing, prioritizing and making rapid site of care decisions for breathless patients presenting to the ED.
Accuracy of bedside ultrasound for the detection of soft tissue foreign bodies by emergency doctors
Authors: Nienaber Anna , Harvey Martyn , Cave Grant
Published: February 2010

Objective:  To assess the ability of emergency physicians and emergency trainees to detect soft tissue foreign bodies using typical ultrasound equipment.

Methods:  Following a 20 min interactive training session, emergency physicians and emergency trainees were assessed on ability to identify subcutaneous foreign bodies (wood, glass, plastic, gravel and metal) embedded in an experimental model containing both sham and real entry point incisions. In the second phase of the experiment accuracy of detection of multiple foreign bodies was assessed in a similar sonographic phantom.

Results:  Six emergency physicians and 14 emergency trainees performed a total of 400 individual sonographic examinations. Emergency physicians correctly identified 29 of 30 foreign bodies and returned sensitivity, specificity, positive predictive value and negative predictive value of 96.7%, 70%, 76.3% and 95.5%, respectively. Trainees correctly identified 60 of 70 foreign bodies and returned sensitivity, specificity, positive predictive value and negative predictive value of 85.7%, 82.9%, 83.3% and 85.3%. Correct identification of the number of foreign bodies present, when multiple, was low (25% physician vs 36% trainee).

Conclusion:  These data suggest ultrasound in the hands of emergency doctors might be useful as an initial screening tool for detection of soft tissue foreign bodies.
Fine‐scale Microhabitat Heterogeneity in a French Guianan Forest
Authors: Baraloto Christopher , Couteron Pierre
Published: February 2010

We examined fine‐scale heterogeneity of environmental conditions in a primary rain forest in French Guiana to describe variation in microhabitats that plants may experience during establishment. We characterized both the range as well as the spatial structuring of 11 environmental factors important for seedling establishment in six hexagonal sampling grids, one each in gap and understory sites at three points representing the predominant geomorphic units in this primary forest. Each grid contained 37 sampling points separated by 31 cm–20 m. Monte‐Carlo tests of semivariograms against complete spatial randomness indicated that for many variables in all six sampling grids, spatial dependence did not exceed 1 m. A principal component analysis of all sampling points revealed a lack of spatial microhabitat structure, rather than homogeneous patches associated with canopy structure or geomorphology. Our results suggest that ample fine‐scale spatial heterogeneity exists to support the coexistence of plant species with differential abiotic requirements for regeneration.
The Effect of Product Variety and Inventory Levels on Retail Store Sales: A Longitudinal Study
Authors: Ton Zeynep , Raman Ananth
Published: February 2010

We examine the effects of product variety and inventory levels on store sales. Using 4 years of data from stores of a large retailer, we show that increases in product variety and inventory levels are both associated with higher sales. We also show that increasing product variety and inventory levels has an indirect negative effect on store sales through their impact on phantom products—products that are physically present at the store, but only in storage areas where customers cannot find or purchase them. Our study highlights a consequence of increased product variety and inventory levels that has previously been overlooked in studies of retail product variety and inventory management. It also quantifies the impact of phantom products on store sales. In addition, our study provides empirical evidence to support earlier claims that higher product variety and inventory levels lead to an increase in defect rate. We discuss the implications of our findings for retail inventory and assortment planning and for the design of retail stores.
Krypton and xenon fractionation in North American tektites
Authors: PALMA R. L. , RAO M. N. , ROWE M. W. , KOEBERL C.
Published: February 2010

Abstract— Elemental and isotopic compositions of the noble gases have been determined in six North American tektites (4 bediasites and 2 georgiaites) and one Ivory Coast tektite. Radiogenically produced 4He may explain the large 4He/36Ar ratios measured relative to air, despite significant diffusive losses. The Ne isotopic composition is enriched in 20Ne consistent with a single stage mass fractionation process. The enormous 20Ne/36Ar enrichments observed in all tektite samples, similar to those reported from other tektites and impact glasses, are attributed to atmospheric diffusion into the samples following solidification. The North American tektites show a systematic increase in 84Kr/36Ar and 132Xe/36Ar relative to air, with enrichments greater than those determined for any other tektite group or terrestrial samples other than shales. These enrichments are inconsistent with existing models of dissolving Kr and Xe in tektite glass without elemental fractionation at atmospheric pressures equivalent to ∼40 km altitude. The Kr and Xe isotopic compositions are indistinguishable from atmospheric within experimental uncertainty.
The Leedey, Oklahoma, chondrite: Fall, petrology, chemistry and an unusual Fe, Ni‐FeS inclusion
Authors: McCOY T. J. , EHLMANN A. J. , MOORE C. B.
Published: February 2010

Abstract— The Leedey, Oklahoma, meteorite shower fell on 1943 November 25, following a fireball which was visible across much of southwestern Oklahoma and northcentral Texas. The shower produced 24 stones with a total mass of ∼51.5 kg. The stones formed a strewnfield ∼18 km in length in the same direction as the observed path of the meteor (N50°W). Leedey is classified as an L6(S3) ordinary chondrite. We report bulk major element chemical analyses from four separate laboratories. Leedey contains an unusual 6 by 8 mm composite Fe,Ni‐FeS grain, which is composed of a 3 mm kamacite grain adjacent to a 5 mm troilite grain. A 50–100 μm rim of high‐Ni (45–55 wt%) taenite (tetrataenite) occurs at the boundary between kamacite and troilite. A single, zoned pyrophanite grain is observed at the boundary between the inclusion troilite and host silicates. An origin as a foreign particle incorporated after metamorphism or during impact melting appears unlikely. This particle likely formed by a complex set of processes, including melting in the nebula, parent body metamorphism and reheating by later shock, mirroring the history of the host chondrite.
Origin of fayalitic olivine rims and lath‐shaped matrix olivine in the CV3 chondrite Allende and its dark inclusions
Authors: KROT Alexander N. , SCOTT Edward R. D. , ZOLENSKY Michael E.
Published: February 2010

Abstract— We have studied an Allende dark inclusion by optical microscopy, scanning electron microscopy, electron microprobe analysis and transmission electron microscopy. The inclusion consists of chondrules, isolated olivines and matrix, which, as in the Allende host, is mainly composed of 5–20 μm long lath‐shaped fayalitic grains with a narrow compositional range (Fa42 ± 2) and nepheline. Olivine phenocrysts in chondrules and isolated olivine grains show various degrees of replacement by 5–10 μm wide fayalitic rims (Fa39 ± 2) and 100–1000 μm wide translucent zones, which consist of 5–20 μm long lath‐shaped fayalitic grains (Fa41 ± 1) intergrown with nepheline. These fayalitic olivines, like those in the matrix of the dark inclusion, contain 10–20 nm sized inclusions of chromite, hercynite, and Fe‐Ni sulfides. The fayalitic rims around remnant olivines are texturally and compositionally identical to those in Allende host, suggesting that they have similar origins. Chondrules are surrounded by opaque rims consisting of tiny lath‐shaped fayalitic olivines (<1–3 μm long) intergrown with nepheline. As in the Allende host, fayalitic olivine veins may crosscut altered chondrules, fine‐grained chondrule rims and extend into the matrix, indicating that alteration occurred after accretion.

We infer that fayalitic olivine rims and lath‐shaped fayalites in Allende and its dark inclusions formed from phyllosilicate intermediate phases. This explanation accounts for (1) the similarity of the replacement textures observed in the dark inclusion and Allende host to aqueous alteration textures in CM chondrites; (2) the anomalously high abundances of Al and Cr and the presence of tiny inclusions of spinels and sulfides in fayalitic olivines in Allende and Allende dark inclusions; (3) abundant voids and defects in lath‐shaped fayalites in the Allende dark inclusion, which may be analogous to those in partly dehydrated phyllosilicates in metamorphosed CM/CI chondrites. We conclude that the matrix and chondrule rims in Allende were largely converted to phyllosilicates and then completely dehydrated. The Allende dark inclusions experienced diverse degrees of aqueous/hydrothermal alteration prior to complete dehydration. The absence of low‐Ca pyroxene in the dark inclusion and its significant replacement by fayalitic olivine in Allende is consistent with the lower resistance of low‐Ca pyroxene to aqueous alteration relative to forsteritic olivine. Hydro‐thermal processing of Allende probably also accounts for the low abundance of planetary noble gases and interstellar grains, and the formation of nepheline, sodalite, salite‐hedenbergite pyroxenes, wollastonite, kirschsteinite and andradite in chondrules and Ca,Al‐rich inclusions.
Ion microprobe study of the Pomozdino and Peramiho eucrites
Authors: HSU Weibiao , CROZAZ Ghislaine
Published: February 2010

Abstract— Electron and ion microprobe measurements of major, minor, and trace element concentrations were made in individual grains of pyroxene, plagioclase, and Ca phosphates in Pomozdino and Peramiho, two eucrites previously classified as anomalous. Although Pomozdino pyroxene is highly magnesian, minor and trace element concentrations in both pyroxene and plagioclase of this meteorite are similar to those in other noncumulate eucrites. High incompatible element concentrations (similar to those in Stannern) coupled with mg# typical of cumulate eucrites confirm the anomalous character of this meteorite but do not allow us to distinguish unequivocally between different possible modes of origin. Peramiho has mg# and trace element concentrations similar to main group eucrites, indicating that this meteorite most probably belongs to this group. A previously reported low incompatible element concentration for Peramiho may be due to a sampling problem.
Magnetic investigations of the West Hawk, Deep Bay and Clearwater impact structures, Canada
Authors: SCOTT Ronald G. , PILKINGTON Mark , TANCZYK Elizabeth I.
Published: February 2010

Abstract— Due to the effects of erosion, tectonism and burial, impact structures are often obscured or destroyed. Geophysical methods are increasingly being used in detecting the signatures of impact structures. While gravity lows associated with impact structures are well understood, associated magnetic anomaly lows are not. In this study, drill cores from three Canadian impact structures were analyzed for rock magnetic properties and mineralogy, in order to explain the magnetic anomaly lows associated with these structures. Samples from the drill cores were cut and measured for anisotropy of magnetic susceptibility (AMS) and natural remanent magnetization (NRM) parameters. Drill cores from the twin impact craters of the Clearwater structure exhibited different NRM characteristics, and samples from their respective drill cores were subject to demagnetization by alternating field and thermal techniques. The difference noted in their NRM characteristics was attributed to the acquisition of a viscous remanent magnetization (VRM) at depth in Clearwater East.

At all three structures, both magnetic susceptibilities and remanent magnetizations are well below regional values in impact generated breccias, melt rocks, shocked crystalline rocks, and in postimpact sedimentary infill. The processes of brecciation, alteration, shock, and infill by nonmagnetic sediments contribute to the development of the magnetic lows. However, a significant contribution to the observed magnetic anomalies was found, by first‐order forward modelling, to arise from basement rocks beneath the impact structures. This zone of reduced magnetization may be caused by the partial demagnetization of magnetite by the impact‐induced transient stress wave traveling away from the point of impact.
A transmission electron microscope investigation of shock metamorphism in olivine of the Ilafegh 013 chondrite
Authors: JOREAU Pascal , LEROUX Hugues , DOUKHAN Jean‐Claude
Published: February 2010

Abstract— Ilafegh 013 is a slightly weathered, type‐3 ordinary chondrite that is unusual in that it is highly shocked. Olivine grains in chondrules were studied in detail by transmission electron microscopy (TEM) to characterize the dislocations, fractures and recrystallization textures. Only c dislocations, in the (010) glide plane, seem to be activated by the shock wave. Fractures are more numerous in the TEM than at the scale of the optical microscope. They can be divided into two groups: (a) Open fractures with injections of molten metal, sulphide, and in some cases, phases containing Ca, Al, Na and K. (b) Very straight and narrow cracks parallel to {130} planes without injected material and consisting of imperfectly relaxed subgrain boundaries composed of two families of dislocations (Burgers vectors a and c). Both types of dislocations are roughly in screw orientation (i.e., the subgrain boundaries have a pronounced twist character). It is suggested that they formed during the shock in order to relax stresses around shear fractures (fractures with displacements of their walls parallel to the fracture plane). Recrystallization occurs in areas where the dislocation density is high. Since diaplectic glass was not detected, it is suggested that recrystallization resulted from the large elastic energy of the lattice defects stored in the deformed crystals.
Fragmentation and hydration of tektites and microtektites
Authors: GLASS B. P. , MUENOW D. W. , BOHOR B. F. , MEEKER G. P.
Published: February 2010

Abstract— An examination of data collected over the last 30 years indicates that the percent of glass fragments vs. whole splash forms in the Cenozoic microtektite strewn fields increases towards the source crater (or source region). We propose that this is due to thermal stress produced when tektites and larger microtektites fall into water near the source crater while still relatively hot (>1150 °C). We also find evidence (low major oxide totals, frothing when melted) for hydration of most of the North American tektite fragments and microtektites found in marine sediments. High‐temperature mass spectrometry indicates that these tektite fragments and microtektites contain up to 3.8 wt% H2O. The H2O‐release behavior during the high‐temperature mass‐spectrometric analysis, plus high CI abundances (0.05 wt%), indicate that the North American tektite fragments and microtektites were hydrated in the marine environment (i.e., the H2O was not trapped solely on quenching from a melt). The younger Ivory Coast and Australasian microtektites do not exhibit much evidence of hydration (at least not in excess of 0.5 wt% H2O); this suggests that the degree of hydration increases with age. In addition, we find that some glass spherules (with <65 wt% SiO2) from the upper Eocene clinopyroxene‐bearing spherule layer in the Indian Ocean have palagonitized rims. These spherules appear to have been altered in a similar fashion to the splash form K/T boundary spherules. Thus, our data indicate that tektites and microtektites that generally contain >65 wt% SiO2 can undergo simple hydration in the marine environment, while impact glasses (with <65 wt% SiO2) can also undergo palagonitization.
Phyllosilicates in the matrix of the unique carbonaceous chondrite Lewis Cliff 85332 and possible implications for the aqueous alteration of CI chondrites
Authors: BREARLEY Adrian J.
Published: February 2010

Abstract— The fine‐grained matrix of the unique, unequilibrated carbonaceous chondrite Lewis Cliff (LEW) 85332 has been studied by scanning electron microscopy (SEM), electron probe microanalysis (EPMA) and transmission electron microscopy (TEM). Compositionally, LEW 85332 has a matrix that is more Fe‐rich than typical CI chondrites but has elemental abundance ratios that appear to be closer to CI matrices than to CM or CR chondrites. The mineralogy of the matrix is dominated by phyllosilicate phases that are predominantly interlayered Fe‐rich serpentine/saponite; anhydrous silicate phases such as olivine and pyroxene are rare. Minor magnetite, troilite and ferrihydrite also occur associated with the phyllosilicates. Despite the high degree of weathering in LEW 85332, the phyllosilicates appear to have an extraterrestrial origin, but the highly variable Mg/Fe ratios of saponite may be the result of partial terrestrial oxidation of Fe‐rich saponite to a more Mg‐rich saponite and ferrihydrite. Alternatively, some of the ferrihydrite may have formed as a result of terrestrial weathering of Fe‐Ni metal. The compositional and mineralogical data suggest that the matrix of LEW 85332 may represent a very early stage in the type of aqueous alteration experienced by the CI chondrites, although it is improbable that LEW 85332 was a precursor to the CI chondrites because of its high abundance of chondrules. The absence of carbonates, the high‐Fe content of the matrix and phyllosilicate phases and relatively low abundance of magnetite all indicate that the degree of oxidation and leaching of LEW 85332 matrix was significantly less than that experienced by the CI chondrites. The absence of clear evidence for alteration of chondrules suggests that either the formation of the hydrous phases in the matrix occurred prior to accretion or that alteration occurred on a parent body and involved limited amounts of fluid, such that the reactions took place preferentially and exclusively within the fine‐grained (anhydrous?) matrix materials.
A survey of clasts and large chondrules in ordinary chondrites
Authors: BRIDGES J. C. , HUTCHISON R.
Published: February 2010

Abstract— We report the results of a survey of clasts and large (>5 mm) chondrules (macrochondrules) within the 833 ordinary chondrites of the Natural History Museum collection. Thirty‐six macrochondrules and 24 clasts were identified and studied. Macrochondrules have textures and mineral assemblages like normal chondrules and so share a common origin. Clasts show evidence for fracturing from larger bodies and can be classified as either: (1) chemically fractionated if they have major and trace‐element compositions differing substantially from most chondrules and clasts; (2) impact melt clasts if they have microporphyritic textures and signs that indicate they are derived from shock‐melted chondritic material; (3) microporhyritic clasts if they are similar to the last category but lack evidence for derivation through shock melting; or (4) indeterminate clasts forming a diverse class that includes all those clasts that do not fit into the other categories.
A new empirical cooling rate indicator for meteorites based on the size of the cloudy zone of the metallic phases
Authors: YANG C. ‐W. , WILLIAMS D. B. , GOLDSTEIN J. I.
Published: February 2010

Abstract—A new empirical cooling rate indicator for metal particles is proposed. The cooling rate indicator is based on the relationship between the size of the island phase in the cloudy zone, which abuts the outer taenite rim (clear taenite I), and the cooling rate of the host meteorite as obtained by conventional metallographic techniques. The size of the island phase was measured by high‐resolution scanning electron microscopy (SEM) in 26 meteorites and decreases from 470 nm to 17 nm, while the cooling rate of the host meteorite increases from 0.5 K/Ma to 325 K/Ma. This island phase size vs. cooling rate relationship is independent of whether the host is an iron, stony‐iron, or stony meteorite and can be used to estimate the low‐temperature cooling rate of the host meteorite. The measurement of the size of the island phase in the cloudy zone can also be applied to a large number of meteorites.
Suevite at the Roter Kamm impact crater, Namibia
Authors: REMOLD Wolf Uwe , KOEBERL Christian , BRANDT Dion
Published: February 2010

Abstract— A small area littered with loose decimeter‐sized fragments of glass and melt fragment‐bearing suevite has been discovered on the western rim of the Roter Kamm impact crater in southern Namibia. The clast population and results of major and trace element chemical analyses are consistent with this breccia having been formed from granitoid basement lithologies only, without contribution from the metasedimentary Gariep and Cenozoic cover sequences. It is assumed that the limited amount of impact melt observed in the Roter Kamm structure could be the result of melt dissipation due to explosive shock‐induced devolatilization of the significant marble component of the Gariep supracrustal cover. Preservation of very limited remnants of impact breccia on the rim of the Roter Kamm crater suggests a relatively deep level of erosion of the crater rim.
Air blast produced by the Meteor Crater impact event and a reconstruction of the affected environment
Authors: KRING David A.
Published: February 2010

Abstract— Using scaling relationships determined from nuclear explosions, the radial extent of the air blast produced by the Meteor Crater impact event is estimated. The wind velocity at a distance of 5 crater radii (3 km) from the point of impact should have exceeded 2000 km/h. Hurricane force winds would have existed as far away as 20 to 40 km, depending on the exact explosive energy of the impact event. To determine how this event may have affected the environment surrounding the crater, the topography, vegetation, and animal life that existed at the time of the impact are reconstructed. For example, if the coniferous woodlands were 100 m lower than they are presently and they had moved farther out onto the plains, then the air blast would have flattened trees within a 16 to 22 km radius of the point of impact and damaged them over an area of 4100 to 8500 km2. The distance over which the damage occurred may have been up to 2× larger in some directions around the crater because of additional effects produced by the ballistic shock wave. Unfortunately, since the trajectory of the projectile is not well known, the direction of the ballistic shock wave effects cannot yet be determined.
A late Triassic age for the Rochechouart impact structure, France
Authors: KELLEY SIMON P. , SPRAY JOHN G.
Published: February 2010

Abstract— Argon‐40/Argon‐39 laser spot fusion dating of pseudotachylyte from the ∼25 km diameter Rochechouart impact structure of western‐central France yields a matrix age of 214 ± 8 Ma (2s̀). Field evidence indicates that the pseudotachylyte was generated during the modification stage of the impact process, probably during transient cavity collapse. This new age is considerably older than the previously accepted age of 186 ± 8 Ma for this structure, which was obtained from hydrothermally‐altered melt sheet samples. The new age is in accordance with earlier paleomagnetic and fission track data, which indicated that Rochechouart was formed during the late Triassic. Moreover, the new determination is in agreement with the regional geological setting and field relations of the structure. The new age of 214 ± 8 Ma falls within the Norian stage of the Triassic system.
Shocked meteorites: Argon‐40‐argon‐39 evidence for multiple impacts
Authors: KUNZ JOACHIM , FALTER MARTINA , JESSBERGER ELMAR K.
Published: February 2010

Abstract—To contribute to the understanding of the impact history of asteroids, we performed a high‐resolution40Ar‐39Ar study of ten moderately to highly shocked chondrites, which we selected according to the shock classification given by Stöffleret al.(1991). Two recent shocked chondrite falls and two highly shocked eucrites completed our sample suite. When possible, we separated impact melt from host rock for separate analysis. In total, we studied 28 samples from 14 meteorites. In some cases, atmospheric Ar that we associate with terrestrial weathering was identified and corrected for. The ages we obtained range between ∼100 Ma and ∼4.1 Ga and are clearly distinct from primordial ages that correspond to solar system formation. We reproduced the previously reported cluster of L‐chondrite ages, ∼500 Ma. The most prominent result of our study is that, in the case of chondrites, melts generally are older than host rocks or melt‐embedded unmolten rocks. To solve this apparent paradox, we propose that the melt‐forming event, which was the most severe shock episode in the history of these meteorites, has not been the only occasion affecting their K‐Ar systems. At least one later impact metamorphism must have occured. The response of the K‐Ar clock to this second event was more severe in the host rock than in the previously (in the first event) generated melt veins and pockets because of different Ar retention rates. Hence, impact metamorphism on meteorite parent bodies indeed was a multistage process extending in time over billions of years.
Chitinozoan biostratigraphy of the early Caradocian Lockne impact structure, Jämtland, Sweden
Authors: GRAHN YNGVE
Published: February 2010

Abstract— The chitinozoan biostratigraphy in seven outcrops and four drilling cores in connection with the Lockne impact structure has been investigated. The impact event took place in early Caradoc (i.e., ∼460.4 Ma ago) and in beds corresponding to the lower part of the Lagenochitina dalbyensis Zone (upper Dalby Limestone). The contact between the impact‐related rocks and the secular postimpact sediments can be traced all over the impact structure, and up to a distance of 50 km away from the presumed crater center. The youngest postimpact sediments in the Lockne impact structure correspond to the lower Örå Shale (Belonechitina hirsuta Zone).
Allan Hills 88019: An Antarctic H‐chondrite with a very long terrestrial age
Authors: SCHERER P. , SCHULTZ L. , NEUPERT U. , KNAUER M. , NEUMANN S. , LEYA I. , MICHEL R. , MOKOS J. , LIPSCHUTZ M. E. , METZLER K. , SUTER M. , KUBIK P. W.
Published: February 2010

Abstract— We have measured the concentrations of the cosmogenic radionuclides 10Be, 26Al and 36Cl (half‐lives 1.51 Ma, 716 ka, and 300 ka, respectively) in two different laboratories by accelerator mass spectrometry (AMS) techniques, as well as concentrations and isotopic compositions of stable He, Ne and Ar in the Antarctic H‐chondrite Allan Hills (ALH) 88019. In addition, nuclear track densities were measured. From these results, it is concluded that the meteoroid ALH 88019 had a preatmospheric radius of (20 ± 5) cm and a shielding depth for the analyzed samples of between 4 and 8 cm. Using calculated and experimentally determined production rates of cosmogenic nuclides, an exposure age of ∼40 Ma is obtained from cosmogenic 21Ne and 38Ar. The extremely low concentrations of radionuclides are explained by a very long terrestrial age for this meteorite of 2 ± 0.4 Ma. A similarly long terrestrial age was found so far only for the Antarctic L‐chondrite Lewis Cliff (LEW) 86360. Such long ages establish one boundary condition for the history of meteorites in Antarctica.
Fayalitic olivine in matrix of the Krymka LL3.1 chondrite: Vapor‐solid growth in the solar nebula
Authors: WEISBERG MICHAEL K. , ZOLENSKY MICHAEL E. , PRINZ MARTIN
Published: February 2010

Abstract— Fayalitic olivine (Fa54–94) is a ubiquitous component in the matrix of Krymka (LL3.1) as well as in other highly unequilibrated chondrites (ordinary and carbonaceous). In Krymka, the fayalitic olivine has an unusual anisotropic platy morphology that occurs in at least five types of textural settings that can be characterized as: (1) isolated platelets, (2) clusters of platelets, (3) euhedral to subhedral crystals, (4) overgrowths of platelets on forsteritic olivine, and (5) fluffy (porous) aggregates. From transmission electron microscope (TEM) investigation, the direction of elongation of the platy olivine overgrowths on forsteritic olivine substrates is along the c axis and in most cases it corresponds with the c axis of the substrate olivine, which suggests that the fayalitic olivine grew in this unusual morphology and is not a replacement product of preexisting material. The fayalitic olivine in the matrix of Krymka is compositionally similar to olivine with platy morphology in the matrix of some CV3 chondrites and both have similar Fe/Mn ratios, but important morphological differences indicate that their relationship needs to be explored further. Textural and compositional data indicate that the fayalitic olivine in the matrix of Krymka, as well as in some other unequilibrated ordinary chondrites, formed prior to final lithification of the meteorite and probably prior to parent body accretion. We find that formation of the fayalitic olivine by vapor‐solid growth provides the best explanation for our observations and data and is the only feasible mechanism for the formation of fayalitic olivine in the matrix of Krymka. We propose that the fayalitic olivine formed by vaporization and recondensation of olivine rich‐dust, during a period of enhanced dust/gas ratio in the nebula.
Cooling rates of diogenites: A study of Fe2+‐Mg ordering in orthopyroxene by single‐crystal x‐ray diffraction
Authors: ZEMA MICHELE , DOMENEGHETTI M. CHIARA , MOLIN G. MARIO , TAZZOLI VITTORIO
Published: February 2010

Abstract— The iron‐magnesium exchange between M1 and M2 sites in orthopyroxene is a reversible reaction that records the latest event in the thermal evolution of the host rock. A kinetic analysis of this process has been applied to 16 orthopyroxene single crystals from 7 different diogenites to constrain the cooling history of their parent body. The Fe2+‐Mg ordering degrees have been determined by single‐crystal x‐ray diffraction. The Fe2+‐Mg ordering closure temperatures were very homogeneous within each sample and ranged, for all diogenites studied, between 311 ± 29 °C and 408 ± 10 °C. Cooling rates at these closure temperatures were calculated using a numerical method developed by Ganguly (1982). These ranged between ∼5 °C/104 year in Johnstown and ∼0.8 °C/year in Roda.

A comparison with other achondrites studied with the same method showed that increasing closure temperatures correspond to increasing cooling rates and that meteorites from a same parent body exhibit similar closure temperature and cooling rate values.

The cooling rates obtained for these diogenites, at their low closure temperatures, should probably be ascribed to a complex thermal history of their parent body, thus confirming Miyamoto and Takeda's theory (1994a) of excavation of deep crustal material due to impact events. The differences on cooling rate values for different diogenites could be due to different burial depths in the fragment ejected from the parent body.
Carbon in howardite, eucrite and diogenite basaltic achondrites
Authors: GRADY M. M. , WRIGHT I. P. , PILLINGER C. T.
Published: February 2010

Abstract—The C contents and isotopic compositions of four eucrites, four diogenites and two howardites have been determined. Stepped heating in an O atmosphere was employed to convert selectively different carbonaceous materials to CO2gas at various temperatures. This technique successfully distinguishes between terrestrial contaminants and indigenous C. With the exception of the Kapoeta howardite, the howardite, eucrite, and diogenite (HED) meteorites contain ∼10–30 ppm indigenous C with δ13C between −29% and −19%. Kapoeta (a regolith breccia) has an elevated C content and δ13C, due to the presence of13C‐enriched carbonate minerals (δ13C ∼ +20%) in CM2‐ or CR2‐like clasts. The range in δ13C displayed by HED samples is similar to that of other solar system basalts, such as lunar rocks and Martian meteorites but distinctly different from that of the terrestrial mantle.

The diogenites have a slightly lower total C yield and higher δ13C than the eucrites, which is a result of degassing of trapped CO/CC2/CO2–3from the silicate lattice during metamorphism or annealing. However, three out of the four diogenites studied appear to contain a discrete component, possibly of graphitic C coating silicate grains, that is seemingly unaffected by the extended annealing period experienced by the diogenites. It is possible that this component might host the indigenous primitive Xe recently identified in diogenites.
Cosmic‐ray exposure ages of diogenites and the recent collisional history of the howardite, eucrite and diogenite parent body/bodies
Authors: WELTEN KEES C. , LINDNER LOUIS , VAN DER BORG KLAAS , LOEKEN THOMAS , SCHERER PETER , SCHULTZ LUDOLF
Published: February 2010

Abstract— We determined the cosmic‐ray exposure age of 20 diogenites from measured cosmogenic noble gas isotopes and calculated production rates of 3He, 21Ne and 38Ar. The production rates were calculated on the basis of the measured chemical composition and the cosmogenic 22Ne/21Ne ratio of each sample. The shielding conditions of each sample were also checked on the basis of the measured 10Be and 26AI concentrations. The exposure ages range from 6 to 50 Ma but do not form a continuous distribution: ten ages cluster at 21–25 Ma and four at 35–42 Ma. The two diogenite clusters coincide with the 22 Ma and 38 Ma peaks in the exposure age distribution of eucrites and howardites. After the selection from literature data of 32 eucrites and 11 howardites with reliable ages, we find a total of 23 howardite, eucrite and diogenite (HED) group meteorites at 20–25 Ma and 10 at 35–42 Ma. The shape of the two peaks is consistent with single impact events, and random number statistics show that they are statistically significant at the 99% level. Altogether, this provides strong evidence for two major impact events 22 Ma and 39 Ma ago. Although these two events can explain more than half of all HED exposure ages, it takes at least five impact events to explain all ages <50 Ma. An impact frequency of one per 10 Ma corresponds to projectiles of at least 2–4 km in diameter for Vesta and of 60–300 m for the 100× smaller Vesta‐derived “vestoids.” Based on the HED exposure‐age distribution, the size distribution of the main‐belt asteroids and the difference in size between Vesta and the kilometer size vestoids, we favor Vesta as the major source of HED meteorites, although some of the meteorites may have been ejected from the vestoids rather than directly from Vesta.
A magma ocean on Vesta: Core formation and petrogenesis of eucrites and diogenites
Authors: RIGHTER KEVIN , DRAKE MICHAEL J.
Published: February 2010

Abstract—Available evidence strongly suggests that the HED (howardite, eucrite, diogenite) meteorites are samples of asteroid 4 Vesta. Abundances of the moderately siderophile elements (Ni, Co, Mo, W and P) in the HED mantle indicate that the parent body may have been completely molten during its early history. During cooling of a chondritic composition magma ocean, equilibrium crystallization is fostered by the suspension of crystals in a convecting magma ocean until the crystal fraction reaches a critical value near 0.80, when the convective system freezes and melts segregate from crystals by gravitational forces. The extruded liquids are similar in composition to Main Group and Stannern trend eucrites, and the last pyroxenes to precipitate out of this ocean (before convective lockup) span the compositional range of the diogenites. Subsequent fractional crystallization of a Main Group eucrite liquid, which has been isolated as a body of magma, produces the Nuevo Laredo trend and the cumulate eucrites. The predicted cumulate mineral compositions are in close agreement with phase compositions analyzed in the cumulate eucrites. Thus, eucrites and diogenites are shown to have formed as part of a simple and continuous crystallization sequence starting with a magma ocean environment on an asteroidal size parent body that is consistent with Vesta.
A flanged toroidal tektite from Australia
Authors: MCCOLL DONALD H.
Published: February 2010

Abstract— The toroidal (doughnut) form of tektite is one of the possible primary forms that could be developed by a spinning globule of molten glass in null gravity. A description is given of a tektite specimen found in the Lake Torrens Region of South Australia. It could have developed from a toroidal primary form, although another way of producing the shape from a core with a deep bubble pit is also suggested.
The Kansas University meteorit
Authors: Schneider D. m. , Benoit P. h. , Sears D. w. g. , Jull A. j. t.
Published: February 2010

Abstract— A new 2.8 kg meteorite find from the United States, Kansas University, is classified as an L6 (S3) chondrite based on optical microscopy and electron microprobe analysis of mafic minerals. Natural thermo‐luminescence (TL) and 14C measurements suggest that the Kansas University meteorite has a short terrestrial age compared to other meteorite finds from this area and is not paired with the other local meteorite finds, Densmore (1879), Lawrence, Kansas and Long Island, Kansas.
Prairie Network fireballs: Data on height, distance and brightness for each measured time‐mar
Authors: Ceplecha Zdenek , Mccrosky Richard E.
Published: February 2010

Abstract— This paper presents data on distance along the trajectory, height and brightness (DTHM‐values) at each measured point (i.e., at each time‐mark) for Prairie Network fireballs photographed between 1963 and 1973. although dthm‐values are not printed here in the “classical” manner as an extensive table, the electronic version of the catalogue belongs to this manuscript as its most substantial part and is accessible from the ftp‐server sunkl.ASU.CAS.CZ (public domain) via anonymous login and under the directory pub in the file pnsao.dat.
Constraints on the anhydrous precursor mineralogy of fine‐grained materials in CM carbonaceous chondrites
Authors: BROWNING Lauren , BOURCIER William
Published: February 2010

Abstract— Mass balance calculations were performed to constrain the precursor mineralogy of fine‐grained, aqueously altered materials in CM carbonaceous chondrites. The bulk composition of unaltered fine‐grained CM materials was estimated and then used to calculate phase proportions for several different initial assemblages. All starting assemblages contain relic, unaltered Fe‐poor phases observed in CM chondrites, plus iron sulfides. The original sources of Fe are uncertain, because most primary Fe‐rich phases were aqueously altered. Four endmember assemblages are considered by adding Fe metal, Fa50, Fa100, or FeO‐rich amorphous materials to the Fe‐poor phases. These represent the Fe‐bearing phases in CM and/or other chondritic classes. Results indicate that the precursor CM assemblage may have contained a maximum of either ∼10 vol% Fe metal, 57 vol% Fa50, ∼28 vol% Fa100, or 37.0 vol% FeO‐rich amorphous materials. Additional calculations were performed in which Fe metal was added to the various FeO‐bearing assemblages. These reveal a strong positive correlation between the forsterite/(forsterite + enstatite) ratio and the amount of FeO‐bearing phases that coexist with metal. If forsterite was more abundant than low‐Ca pyroxene in the accreted CM materials, then these materials must have also contained significant amounts of FeO‐rich phases (e.g., at least 36 vol% Fa50, 10 vol% Fa100, or 17 vol% FeO‐bearing glasses). Calculated mineral proportions suggest that intact calcium‐aluminum‐rich inclusions (CAIs) represent only about one‐half of the original CAI budget, which is consistent with previous hypotheses that the initial CAI contents of CM and CO chondrites were similar. Some similarities exist between the primary CM assemblages calculated here and the mineralogies of other chondrite classes, but the initial CM materials do not appear to be represented in our meteorite inventory.
Microimpact phenomena on Australasian microtektites: Implications for ejecta plume characteristics and lunar surface processes
Authors: PRASAD M. SHYAM , SUDHAKAR M.
Published: February 2010

Abstract— Detailed investigations of the microimpact phenomena on Australasian microtektites from four samples from the Central Indian Basin reveal an array of features, such as very low‐velocity captured droplets, welded projectiles, angular fragments and dust, craters generated by projectiles defining an oblique trajectory, high‐velocity “pitless” craters, and the conventional hypervelocity craters with well‐defined central pits and radial and concentric cracks—found commonly on lunar surface materials. The microimpacts are a consequence of interparticle collisions within the ejecta plume (as suggested by their chemistry) subsequent to a major impact and, therefore, reveal processes inherent in an impact‐generated plume. All the impact phenomena observed here have taken place while the targets and projectiles were in flight and are therefore secondary impacts in lunar terms. However, some of the resultant features are analogous to lunar micro‐craters attributed to primary impacts by cosmic dust. Therefore, ballistic sedimentation on the Moon is likely to contain plume collisional debris as well.