bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficacy and safety of bipolar electrode grasping forceps for laparoscopic myomectomy in uterine cervical myoma
Authors: Higuchi Y , Okuda K , Nakamura Y. , Hayashi A , Hayashi M , Fujiyama F , Yoshida Y , Yamashita Y , Terai Y , Kamegai H , Ohmichi M
Published: June 2012

Introduction

Myomectomy for cervical myoma is problematic because cervical myomas are very close to neighboring structures, such as the ureters, uterine artery, bladder and rectum. There are a few reports on laparoscopic myomectomy for cervical myomas to avoid blood loss, such as occlusion of iliac arteries and clipping of the uterine artery. We evaluated the efficacy and safety of bipolar electrode grasping forceps for laparoscopic myomectomy in uterine cervical myoma.

Methods

From November 2006 to May 2009, eight women with uterine cervical myoma underwent laparoscopic myomectomy. We employed electrode grasping forceps with a combination of two tenaculums for separating and securing hemostatsis.

Results

Seven of eight cases were successfully treated by laparoscopic myomectomy, but one patient, with a large 900‐g myoma was converted to the laparotomy as a result of blood loss (1800 mL). Among the other seven cases, the average weight of the myoma was 132 g (range, 16–310 g) and the operating time was 176 min. (range, 125–255 min). No complications occurred. Of the four cases who wanted to become pregnant postoperatively, two became pregnant and delivered by Caesarean section.

Conclusion

These findings indicate that bipolar electrode grasping forceps using two tenaculums for traction of the myoma are useful for laparoscopic myomectomy in cervical myomas.
Phylogeographic studies of plants in China: Advances in the past and directions in the future
Authors: LIU Jian‐Quan , SUN Yong‐Shuai , GE Xue‐Jun , GAO Lian‐Ming , QIU Ying‐Xiong
Published: June 2012

Abstract  Phylogeography has been one major focus of evolutionary biology in recent years, with many important advances in Chinese species. In this issue, we collected 11 phylogeographic studies of plants by Chinese laboratories. We further synthesized the main findings and patterns emerging from these and previous phylogeographic studies in China and asked where phylogeographic research should be directed in the coming years. Numerous examples have shown that phylogeographic patterns in China did not show an expected expansion–contraction pattern at large scale, mirroring the geological records showing that no unified ice sheet had developed in China during the Quaternary Period. Instead, regional expansions and intraspecific divergences are very common in most studied species during the Quaternary oscillations. Different intraspecific lineages or alleles (haplotypes) were detected in multiple localized refugia, from where regional or local expansions are likely to have started. Hybridizations and introgressions are frequent between intraspecific lineages or between different species. We also reviewed computational methods for phylogeographic analyses. Despite the great progress made in recent years, there remains much to discover about the spatial–temporal dimensions and underlying speciation mechanisms of Chinese plants. Phylogeographic studies represent a key knot that connects the genus phylogeny (macroevolution) and speciation and adaptation (microevolution). Therefore, we advocate that: (i) phylogeographic studies of plants in China should be directed to the closely related species or a monophyletic group (for example, a genus or a section) in the coming years; and (ii) population genetic data based on direct sequencing multiple loci, especially those from nuclear genome and statistical tests should be widely adopted and enforced. The recovered intraspecific divergences and phylogeographic patterns of multiple‐species may allow us to better understand the high plant diversity in China and set up concrete hypotheses for studying plant speciation and diversification mechanisms in this region.
Effect of storage media and time on the fracture toughness of resin‐based luting cements
Authors: Azar MR , Bagheri R , Burrow MF
Published: June 2012

Background:  Resin‐based cements are brittle materials and the major shortcomings of these materials are manifested in their sensitivity to flaws and defects. Although various mechanical properties of resin luting cements have been described, few fracture toughness test data for resin‐based luting cements using the short rod design have been published.

Methods:  Specimens were prepared from five resin luting cements. For each material a total of 36 disc‐shaped specimens were prepared using a custom‐made mould. Specimens were randomly divided into six groups of six, immersed in two solutions: distilled water and 0.01 mol/L lactic acid at 37 °C for 24 hours, 1 month or 3 months. The specimens were loaded using a universal testing machine. The maximum load at specimen failure was recorded and the KIc (MPa. M 0.5) was calculated.

Results:  There was a relationship between material, storage solution and time (p < 0.05). Nexus 3 showed the highest KIc followed by Panavia F, Calibra, Smart Cem2 and seT.

Conclusions:  The fracture toughness of the resin luting cements was affected by both time and storage solution. Comparable fracture toughness of conventional resin cement and self‐adhesive resin cements was observed.
Toxoplasma gondii in Ireland: Seroprevalence and Novel Molecular Detection Method in Sheep, Pigs, Deer and Chickens
Authors: Halová D. , Mulcahy G. , Rafter P. , Turčeková L. , Grant T. , de Waal T.
Published: June 2012

Toxoplasma gondii is among the most studied parasites worldwide but there is not much information about it published in Ireland. The objectives of this study were to determine the seroprevalence of T. gondii in sheep, pigs, deer and chickens and the molecular detection of T. gondii DNA in muscle tissue. Serum samples were collected from these species at the time of slaughter at Irish abattoirs during 2007 and tested for anti‐T. gondii antibodies using a commercial semi‐quantitative latex agglutination test. Antibodies (titre ≥1 : 64) were found in 36% (105/292) sheep, 4.7% (15/317) pigs and 6.6% (23/348) deer. In chickens, 18% (65/364) had antibody titres, ranging between 1 : 5 and 1 : 1024. Significant (P ≤ 0.05) age‐related differences in seroprevalence were found in adult sheep (58.1%) and pigs (23.1%). Significant gender differences in seroprevalence was also found in sheep with more females (43%) than males (22.4%) being positive. However, when adjusted for age through logistic regression gender was no longer significant. Seroprevalence was also evaluated on farm locations grouped to NUTS level 3, but the prevalence was too low to draw any statistical conclusions. Using a nested PCR, the presence of T. gondii DNA was detected in diaphragm samples from 3.6% (3/83) sheep, 13.0% (3/23) pig and 4.2% (3/71) deer. Meat digestion liquids from a Trichinella spp. survey in pigs were also used for the first time to detect T. gondii. Toxoplasma gondii DNA was detected in 50% (10/20) of pooled samples. This is the first in depth study of T. gondii seroprevalence in animals in Ireland and a novel method, using digestion liquid from pooled diaphragm samples, for PCR detection in pigs is described.
The “Tree Meteorite” of La Pine, Oregon*
Authors: Pruett J. Hugh
Published: June 2012

Abstract On August 16, 1938, the Portland Oregonian carried on its front page a story of the finding of a white‐hot meteorite in a hole in a fir tree about 60 feet from the ground. It was said that it had cut through 14 inches of the side of the tree. The story spread all over the country. The writer saw it in Time and in the Christian Science Monitor. Attempts were made by interested persons to obtain samples for inspection, but the holder refused all requests. He would not let even newspaper men see it! Two forestry officials finally got a glimpse of it. They reported that it was light in color and weight and full of holes. It was soon learned through the Forestry Department that “tree meteorites” had several times previously been reported in the Pacific Northwest. Analyses of these objects had revealed a composition about like that of the ashes from sound wood in the same trees. Very little iron (only traces) and no nickel have been found. It is thought that these clinkers are formed when the top of a tree is burned off by forest fires and ashes sink down into the trunk, perhaps into a rotten spot, and there fuse into a solid mass by the intense heat of the surrounding burning wood.
How the Casas Grandes, Chihuahua, Mexico, Meteorite got to Washington, D. C
Authors: Monnig Oscar E.
Published: June 2012

Abstract A quotation from the life story of August Santleben tells of his obtaining and transporting by wagon the Casas Grandes, Chihuahua, Mexico, iron meteorite of nearly 1 3/4 tons' weight. He took it from Chihuahua, via Ft. Davis, Ft. Stockton, and San Antonio, to Luling, Texas, whence it was shipped, apparently by rail and water (through Galveston), to the Centennial Exposition at Philadelphia, Pennsylvania. The account fills a gap in the history of the meteorite, throws some light on the conflicting stories of its early owners and possessors, and mentions the unique doctrine that all meteorites are the inherent property of the government and not subject to individual ownership.
Some Properties of the Beenham, New Mexico, Aërolite
Authors: Leard Robert M.
Published: June 2012

Abstract and Introduction

The following description of an aërolite from Beenham, Union County, New Mexico, is offered as part of the work in a special course in meteoritics in the Department of Astronomy of the University of California, Los Angeles. Two fragments, weighing 14 1/2 g. and 1 1/2 g., of the aërolite, were secured, and from this material three thin sections and one polished section were prepared for investigation. Four photomicrographs were taken, and the relationships and optical properties of the various minerals were determined. The writer wishes to thank Dr. H. H. Nininger of the American Meteorite Laboratory, Denver, Colorado, for donating the material used, and Dr. Frederick C. Leonard of the Department of Astronomy of the University of California, Los Angeles, under whose guidance this study was made.
The Puente‐Ladron, Socorro County, New Mexico, Aerolite
Authors: Nininger H. H.
Published: June 2012

This paper contains an account of a recently discovered 7.7‐gram aerolite (a chondrite) (Puente‐Ladron, Socorro County, New Mexico; coördinate number = 1068,344), together with an invitation on the part of the finder to all members of the S. R. M. to participate in a search for additional fragments of the fall.
A Photograph of a Meteor Trail Made with the Crossley Reflector
Authors: Herbig George H.
Published: June 2012

A description is given of the trail of a bright meteor appearing on a recent Crossley Reflector plate, and an attempted method of detecting the effect of the angular diameter of the meteor is outlined. A photographic light curve of the meteor was obtained and is shown in an accompanying diagram (Figure 2).
An Unusual Photograph of a Meteor
Authors: Buddhue John Davis
Published: June 2012

ABSTRACT AND INTRODUCTION

As far as I am aware, the accompanying photograph (Figure 1), obtained on October 15, 1934, at Claremont, California, is the only picture of a meteor trait which seems to show evidence of a wind at a high altitude in the Earth's atmosphere, altho several pictures of meteor trains* showing such evidence are in existence. The present photograph appears to be also the only picture exhibiting the meteorite within its gas cloud, unless the photograph secured by Charles M. Brown and reproduced as Figure 1 in P. A., 42, 291, 1934, and as Figure 3 in C.S.R.M., 1, No. 2, 38; P. A., 44, 387, 1936, should be counted. In that photograph, two bodies appear to be about to emerge from a gas cloud.
On the Puente‐Ladron, New Mexico, Aerolite
Authors: La Paz Lincoln
Published: June 2012

C. H. Smith's assertion that “The main facts are against the possibility that this little aerolite was carried into the area by Indians and there discarded or lost; …” is shown to be without foundation. Accordingly, Smith's plea for an all‐out search of the inhospitable and unpromising Puente‐Ladron area is without justification. In view of the failure of continued search in this region to result in additional finds, it would be more reasonable to exhort meteoriticists to increased activity in areas known to be meteorite‐strewn fields.
A General Definition of the Coördinate Number of a Meteoritic Fall
Authors: Leonard Frederick C.
Published: June 2012

A general definition of the coördinate number (C.N.) of a meteoritic fall is given, and, in view of that definition, certain recommendations concerning the use of C.N.'s are made; also, simple notations for indicating negativity in C.N.'s are proposed.
The Polar Coördinate Number of a Meteoritic Fall*
Authors: Leonard Frederick C.
Published: June 2012

The polar coördinate number (PCN) of a meteoritic fall is defined and compared with the previously introduced coördinate number, now called, for distinction, the equatorial coördinate number (ECN). Each variety of number has its own peculiar advantages, which are briefly discussed.
The Glorieta Mountain, New Mexico, Siderite (ECN=+ 1058,356)*
Authors: Beck Carl W. , La Paz Lincoln , Stevenson Ralph G.
Published: June 2012

Abstract

The history of the recovery of the masses that comprize the Glorieta Mountain, New Mexico, siderite is reviewed. The present paper is based on a detailed mineralogical, metallographical, and chemical investigation of the remarkable cane‐shaped specimen from the Department of Geology of the University of New Mexico. The meteoritic constituents present are kamacite, taenite, plessite, schreibersite, and lawrencite. The meteorite is classified as a medium octahedrite (Om).
The Achilles, Rawlins County, Kansas, Chondrite (ECN =+ 1008,398)
Authors: Stockwell H. O. , Morley Russell A.
Published: June 2012

The discovery of the Achilles, Rawlins County, Kansas, meteorite (ECN = + 1008,398; cl. = veined crystalline chondrite, Cka) was made by the Homedale brothers in 1924. The meteorite remained unrecognized for 26 years, until Mr. Anthony Halner noticed the similarity between it and specimens in the H. O. Stockwell display at the Kansas State Fair. The meteorite weighs 12,020 gm. and is covered by a fusion‐crust. The original weight is estimated as 16 kg. The meteorite is preserved in the collection of Mr. Stockwell.
ON THE CONSTANCY OF COSMIC SPHERULE INFLUX DURING THE QUATERNARY
Authors: Utech Karl
Published: June 2012

The influx rate of cosmic spherules can be measured on sediments of which the rate of deposition is known. It proved to be constant over long geological periods.

Also, deposits of homogeneous composition in which the spherule concentration did not fluctuate appear to prove that the influx rate of cosmic spherules remained constant when the respective sediments had been laid down. Certain deep‐sea cores are particularly suited for such an investigation.

The deep‐sea sediments from which the author has drawn his conclusions are of quaternary age.
THE CHEMISTRY OF HAVERÖ UREILITE
Authors: Wänke H. , Baddenhausen H. , Spettel B. , Teschke F. , Quijano‐Rico M. , Dreibus G. , Palme H.
Published: June 2012

The concentrations of 41 major, minor and trace elements were determined in Haverö ureilite. In addition to the analysis on bulk samples a number of separates were measured, too, including hand‐picked samples of the dark carbonaceous, diamond‐rich inclusions and two metal fractions. It was found that one metal fraction had an extraordinarily high Ir/Au‐ratio of 19. According to the concentrations of the noble metals and of nickel, gallium, tungsten and rhenium this metal represents, most probably, the siderophile portion of a high temperature condensate, i.e., the pattern of these elements is very similar to that found in Allende inclusions (Wänke et al., 1972)
EQUILIBRIUM CONDENSATION IN A SOLAR NEBULA
Authors: Arrhenius Gustaf , De Bibhas R.
Published: June 2012

In attempts to reconstruct the environment of condensation of solar system materials, particularly exemplified by certain meteorite components, the relative temperatures of the gas and the solid are of critical importance. The relationships that determine the heat balance in a circumsolar grain‐gas system are examined. Fundamental considerations show that regardless of opacity or gas density, the gas will always be at a higher temperature than the solid in such regions of the system where condensation is possible. Implications of the characteristic temperature differential between the gas and the condensing solid are discussed.
A REFRACTORY GLASS CHONDRULE IN THE VIGARANO CHONDRITE
Authors: Reid Arch M. , Williams Richard J. , Gibson Everett K. , Fredriksson Kurt
Published: June 2012

Vigarano, a type 3 carbonaceous chondrite, contains a chondrule composed of highly refractory Ca and Al rich glass with minor spinel. The chondrule formed from material similar to the Ca, Al, Ti‐rich aggregates that are common in Vigarano and other type 3 chondrites and formation of these refractory aggregates must predate formation of some Vigarano chondrules. Experiments with synthetic analogues and a comparison with studies in the system CaO‐MgO‐Al2O3‐SiO2 indicate a temperature for formation of the chondrule at or above 1700 °C followed by very rapid cooling.
THE NAKHLITES PART I: PETROGRAPHY AND MINERAL CHEMISTRY
Authors: Bunch T. E. , Reid Arch M.
Published: June 2012

The only two Nakhlite meteorites, Nakhla and Lafayette, are identical in mineral composition, consisting of augite (Wo39En38Fs23), olivine (Fo32–35), plagioclase (An27), K‐feldspar (Or75Ab22An3), titaniferous magnetite with exsolved ilmenite, iddingsite (?), and minor amounts of fluor‐chlorapatite, FeS, pyrite, chalcopyrite, and K‐rich glass. The texture is suggestive of a cumulative origin.
THE NAKHLITES PART II: WHERE, WHEN, AND HOW
Authors: Reid Arch M. , Bunch T. E.
Published: June 2012

The Nakhla and Lafayette meteorites are pyroxenite cumulates that show no simple relation to chondrites, basaltic achondrites, or lunar rocks. They present evidence of magmatic activity occurring on a highly differentiated parent body relatively late in the history of the solar system similar in some respects to the Earth.
METAL OF HIGH Co CONTENT IN LL CHONDRITES
Authors: Sears D.W. , Axon H.J.
Published: June 2012

Measurements on the metal of the LL chondrites Appley Bridge, Jelica, Olivenza, and Khanpur have shown that the Co: Ni ratio of the metal is near 1.24 and that Prior's law appears to be followed to some extent within the LL group.
AÏOUN EL ATROUSS: A NEW HYPERSTHENE ACHONDRITE WITH EUCRITIC INCLUSIONS
Authors: Lomena Ibeke S. M. , Touré Fadel , Gibson Everett K. , Clanton Uel S. , Reid Arch M.
Published: June 2012

Preliminary investigations have been made on two separate pieces from the Aïoun el Atrouss meteorite that fell on April 17, 1974 in southeast Mauritania. The major portion of the meteorite is a brecciated hypersthene achondrite with orthopyroxene (En74) as the major phase. Clasts of eucrite, up to 7 percent in volume within a single slice, occur within the hypersthene achondrite host. No evidence has been found of reaction between the two meteorite types, nor of the presence of any materials intermediate in composition.
26AI LOSSES FROM WEATHERED CHONDRITES
Authors: Herzog G. F. , Cressy P. J.
Published: June 2012

He, Ne and Ar have been measured in 8 samples of Dalgety Downs (DD) and 5 samples of Ness County, 1894 (NC). 26Al, K, Th and U have been measured in 4 samples of DD and the chondrites Etter, Bledsoe, Seminole #2 and Zerga. Weathering probably explains the correlation between 26Al and 21Ne in DD, the independence of 3He/21Ne and 22Ne/21Ne in DD and NC and the > 2σ reduction of all 26Al contents from calculated saturation values.
TYSNES ISLAND: AN UNUSUAL CLAST COMPOSED OF SOLIDIFIED, IMMISCIBLE, Fe‐FeS AND SILICATE MELTS
Authors: Wilkening Laurel L.
Published: June 2012

In the Tysnes Island gas‐rich, H4 chondrite an inclusion was found which consists of two distinct portions: a tear‐drop shaped Fe‐FeS eutectic‐like intergrowth (0.5 cm greatest dimension) and a silicate consisting primarily of olivine in glass. The boundary between the two portions of the inclusion is smooth. Nickel is enriched in the metal at the metal‐sulfide boundaries and in nodules within the metal. The subhedral to skeletal olivine in the silicate portion is forsteritic, Fo75–90. The glass is very rich in SiO2, up to 70%. The glass is not homogeneous, but a fairly typical analysis is SiO2, 66.9%; TiO2, 0.4; Al2O3, 0.4; Cr2O3 0.3; Na2O, 3.3; K2O, 0.9; CaO, 6.0; Fe, 10.9; Mg, 2.0. The Fe‐FeS and silicate portions appear to have separated from one another as immiscible liquids. The modal composition of each portion agrees well with compositions predicted for a total melt of an H‐group chondrite. This inclusion seems to be a “snapshot” of the process of metal‐silicate fractionation which Fodor and Keil (1976) have previously suggested must exist to explain the presence of metal‐ and sulfide‐free inclusions in brecciated chondrites.
THE MINERALOGY OF A RHÖNITE‐BEARING CALCIUM ALUMINUM RICH INCLUSION IN THE ALLENDE METEORITE
Authors: Fuchs Louis H.
Published: June 2012

The meteoritic occurrence of rhönite‐bearing calcium and aluminum rich inclusions (CAIs) appears to be restricted to the Allende meteorite. These inclusions, however, are very scarce as only four are known to the author. This report is primarily concerned with the descriptive mineralogy of one of these rare CAIs.

The inclusion contains, in decreasing order of abundance, melilite (Ak15‐Ak55), spinel, fassaite, rhönite, perovskite, grossular, Ni‐Fe metal, hibonite, troilite, a vanadium‐iron oxide (20–27 wt % V2O3), molybdenite, geikielo‐ilmenite and magnetite. Although this mineral assemblage formed under nonequilibrium conditions from a molten drop, the coarse grained texture does not indicate rapid crystallization. Local chemistries evidently played a significant role in the formation of metastable phase relationships and symplectites, thereby confounding the construction of a plausible thermal history for this CAI.
A NEW SPECIMEN OF THE MOUNT DOOLING IRON METEORITE FROM MOUNT MANNING, WESTERN AUSTRALIA
Authors: De Laeter J.R.
Published: June 2012

A 701 kg iron meteorite has recently been discovered near the Mount Manning Range in Western Australia. The meteorite has a fan‐shaped or delta wing configuration, one side being smooth and slightly concave with a well‐defined fusion crust, whilst the other side is rough, convex and possesses numerous regmaglypts. It is probable that the meteorite pentrated much of the earth's atmosphere in an aerodynamically stable orientation, typical of the stalled attitude of delta wing aircraft. The meteorite is a member of Chemical Group 1C. A comparison of the chemical composition, surface features, microstructure and location of this meteorite with the Mount Dooling meteorite confirms that the find is a larger specimen of Mount Dooling. It is possible that other fragments of the Mount Dooling meteorite may be found in the Mount Manning Range region.
AN H4–6 CHONDRITE: MOTTA DI CONTI
Authors: Levi‐Donati G.R. , Maras A. , Sighinolfi G.P.
Published: June 2012

The mineralogical and chemical compositions of meteorites from the Motta di Conti, Vercelli, Italy, shower (February 29, 1868) have been determined. Microprobe analyses, of olivine (Fa19,6) and orthopyroxene (Fs17,8), as well as the bulk chemical composition, particularly the ratios of SiO2/MgO (1.50), Fe°/Ni° (11.03), Fetotal/SiO2 (0.81), Fe°/Fetotal (0.70) and the content of Fetotal (28.60%) classify the meteorite as an H‐group chondrite. The percentage of total metallic nickel‐iron (22.06%) is somewhat higher than the average in H‐group chondrites. The texture of our stone shows evidence of metamorphism. The integration between matrix and chondrules is advanced and may suggest a high petrographic grade, but the identification of several microscopic features (e.g. small grains of monoclinic twinned pyroxene, FeNi‐FeS intergrowths, globules and mosaic) leads to the conclusion that a variety of petrographic types (4–6) are present. Metamorphic equilibration in chondrites is discussed and a preliminary hypothesis for H4–6 chondrites is suggested.
THERMAL HISTORY OF THE ABEE ENSTATITE CHONDRITE II; THERMAL MEASUREMENTS AND HEAT FLOW CALCULATIONS
Authors: Rudee M.L. , Herndon J.M.
Published: June 2012

Specimens from the center and the outer surface of Abee exhibit identical microstructures within their metal phase—platelets of an iron carbide. Thus the entire body must have cooled at a nearly uniform rate. The density, heat capacity, and thermal conductivity have been measured and used in a theoretical heat flow analysis. From these calculations and observations it is concluded that Abee cooled from 700 °C to 200 °C in about two hours.
UNUSUAL WEATHERING PRODUCTS OF OLDHAMITE PARENTAGE IN THE NORTON COUNTY ENSTATITE ACHONDRITE
Authors: Okada Akihlko , Keil Klaus , Taylor G.J.
Published: June 2012

White, pale‐yellow and brown deposits occur on surfaces of fragments of the Norton County enstatite achondrite. X‐ray powder analysis of these materials indicates that they consist of several calcium‐bearing minerals: portlandite [Ca(OH)2], vaterite (CaCO3, hexagonal), calcite (CaCO3, trigonal) and bassanite (CaSO4‐1/2 H2O). We suggest that these minerals formed by weathering of oldhamite (CaS), which we found to occur in Norton County. The occurrence of portlandite suggests that at low temperatures and in the terrestrial environment, hydrolysis of oldhamite is the most important first step in the weathering sequence. Subsequent carbonation of portlandite is thought to produce vaterite, and vaterite in turn might transform into calcite. Thus, we suggest a weathering sequence in the terrestrial environment of oldhamite portlandite vaterite calcite. The mineral bassanite is clearly also a terrestrial weathering product but its precise mode of origïn is somewhat uncertain: in the system CaSO4‐H2O, bassanite forms from gypsum at about 100 °C (an unlikely high T for the weathering environment of Norton County).
A METHOD FOR THE IDENTIFICATION AND ELIMINATION OF CONTAMINATION DURING CARBON ISOTOPIC ANALYSES OF EXTRATERRESTRIAL SAMPLES
Authors: Swart P.K. , Grady M.M. , Pillinger C.T.
Published: June 2012

The study of carbon abundance and isotopic composition in extraterrestrial samples is fraught with problems related to contamination in the terrestrial environment and during sample handling. A stepped combustion method is described which demonstrates that progress can be made towards resolving the indigenous species from contamination which for the most part burns at low temperature (< 425 ± 25 ±C). The proposed method is not applicable to samples which have indigenous phases burning at low temperatures e.g. the C1 and C2 carbonaceous chondrites. A number of examples where its application is possible are given.

Even meteorites collected immediately after their fall, such as Allende, contain a proportion of extraneous carbon which has deleterious effects on any bulk estimate of isotopic composition. “Falls” which have spent a considerable time in museum collections and “finds” (other than Antarctic samples) can be considered as grossly contaminated. Bulk isotope and carbon abundance measurements in the literature for most samples having less than 1 wt% C are thus of questionable value. Antarctic samples have much less contamination of an organic nature but all seem to contain a weathering component which can be easily recognised and hence disregarded in estimates of bulk composition. Stepped combustion, applied to an Apollo 11 lunar soil which has not been specially stored and which now contains, due to contamination, nearly twice as much carbon as when originally collected, can still afford data closely resembling those obtained from the sample when it was first returned to Earth.
DISTRIBUTION OF RARE EARTH ELEMENTS AND URANIUM IN VARIOUS COMPONENTS OF ORDINARY CHONDRITES
Authors: Ebihara Mitsuru , Honda Masatake
Published: June 2012

Rare earth elements (REE) and uranium were studied for their distributions in various component phases of four ordinary chondrites, Kesen (H4), Richardton (H5), Bruderheim (L6), and Saint Séverin (LL6). A selective dissolution method was applied for the phase fractionation. The REE were analysed by neutron activation analysis, and U was determined by neutron‐induced fission tracks. The present study revealed that both REE and U are highly enriched in the Ca‐phosphate minerals with different enrichment factors, implying chemical fractionation between them. The phosphates seem to be responsible for more than 80% of the light REE in all chondrites. On the other hand, only 20–40% of the total U resides in the Ca‐phosphates. This difference in enrichments might have been caused through the levels of metamorphic activity on the meteoritic parent bodies.
THE MACHINGA, MALAWI, METEORITE: A RECENT L6 FALL
Authors: Graham A.L. , Crow M.J. , Chatupa J.C. , Mndala A.T.
Published: June 2012

The Machinga meteorite fell in the Southern Province of Malawi on January 22, 1981, at approximately 1000 hours local time. The fall site is about 7.5 km SW of Machinga and has the co‐ordinates 15° 12′44″ S., 35°14′32″ E. A single crusted mass weighing 93.2 kg was recovered. The Machinga meteorite is an L6 chondrite with olivine Fa24.5 and orthopyroxene Fs21.1. The silicates have a granular texture and the stone has been shocked.
PHOSPHATE‐SULFIDE ASSEMBLAGES AND Al/Ca RATIOS IN TYPE‐3 CHONDRITES
Authors: Rubin Alan E. , Grossman Jeffrey N.
Published: June 2012

Phosphate‐sulfide assemblages are common constituents in type‐3 carbonaceous and ordinary chondrites. CV3 chondrites contain assemblages of pentlandite‐merrillite and troilite‐merrillite as well as isolated grains of Ca‐pyroxene; CO3 chondrites contain troilite‐merrillite (± schreibersite) as well as isolated grains of plagioclase; and, H‐L‐LL3 chondrites contain troilite‐merrillite (± metal), troilite‐chlorapatite, and metal‐chlorapatite. The phosphate‐bearing assemblages probably formed in the following manner: (1) metal grains with significant P formed in the nebula at high temperatures; (2) Schreibersite exsolved and crystallized at metal grain boundaries during cooling; (3) some metal grains were sulfurized at lower temperatures by H2S; (4) the metal‐schreibersite and sulfide‐schreibersite assemblages accreted rims of finegrained silicates; and, (5) the Schreibersite reacted with Ca, O and Cl from these silicates to form merrillite and chlorapatite.

The reported bulk compositions of chondritic constituents have ***CI‐normalized Al/Ca ratios >1, whereas whole‐rock ratios are unfractionated. Even though the phosphate‐bearing assemblages and isolated grains of Ca‐bearing silicates are ubiquitous in type‐3 chondrites, they are insufficiently abundant to lower the Al/Ca ratios of the major chondritic components to those of the whole‐rocks. It seems probable that some of the analytical data are incorrect; bulk compositions determined by microprobe may yield erroneously high Al/Ca ratios if samples are analyzed with a broader electron beam than used for analyzing the standards. We recommend analyzing standards and samples with the same size beam.
CHEMICAL VARIATIONS AMONG L‐CHONDRITES—IV. ANALYSES, WITH PETROGRAPHIC NOTES, OF 13 L‐GROUP AND 3 LL‐GROUP CHONDRITES
Authors: Jarosewich Eugene , Dodd Robert T.
Published: June 2012

We review our procedures for selecting, preparing and analyzing meteorite samples, present new analyses of 16 ordinary chondrites, and discuss variations of Fe, S and Si in the L‐group. A tendency for Fe/Mg, S/Mg and Si/Mg to be low in L chondrites of fades d to f testifies that post‐metamorphic shock melting played a significant role in the chemical diversification of the L‐group. However, these ratios also vary widely and sympathetically in melt‐free chondrites, indicating that much of the L‐group's chemical variation arose prior to thermal metamorphism and is in that sense primary. If all L‐chondrites come from one parent body, type‐correlated chemical trends suggest: 1) that the body had a traditional “onion skin” structure, with metamorphic intensity increasing with depth; and 2) that it formed from material that became more homogeneous, slightly poorer in iron, and significantly richer in sulfur as accretion proceeded.
SOME MORPHOLOGIC SYSTEMATICS OF COMPLEX IMPACT STRUCTURES
Authors: Pike R.J.
Published: June 2012

Similarities among impact structures on different planets and satellites suggest that the cratering process transcends variations in both target and impactor. In particular, impact may control the spacing of concentric rings, if not their actual emplacement. In at least four respects the scaled horizontal dimensions of complex meteorite‐impact structures on Earth resemble those of multi‐ring basins and large craters on the Moon, Mars, Mercury, and some outer satellites: (1) Base diameter of the (topographic) central peak is a constant 20% to 25% of the rim diameter in small complex craters; (2) it averages only half as much in large structures that also have concentric rings; (3) the inner ring of a two‐ring crater lacking a central peak is half the diameter of the outer ring; (4) adjacent rings of complex craters that have more than two concentric rings are spaced at a constant interval of about (2.0 ± 0.2)0.5 D, both inside and outside the main ring. Two minor differences in morphology suggest that uniquely terrestrial conditions may control some horizontal dimensions of meteorite craters: (1) the inner ring of a two‐ringed structure that also has a central peak is 0.5X the diameter of the outer, not 0.4X as it is for peak‐plus‐ring basins on the planets; and (2) two‐ring and multi‐ring meteorite craters occupy the same size range, whereas on planets most two‐ring basins are smaller than multi‐ring basins.
RARE EARTH AND OTHER ELEMENTS IN COMPONENTS OF THE ABEE ENSTATITE CHONDRITE
Authors: Frazier Robert M. , Boynton William V.
Published: June 2012

Abee clast samples, a matrix sample, a dark inclusion, magnetic and nonmagnetic samples, and bulk samples were analyzed by neutron activation analysis (NAA). The REE were determined by radiochemical NAA. Na, K, Sc, Cr, Mn, Fe, Co, Ni, Zn, As, Se, Sm, Ir, Au were determined by instrumental NAA.

High abundances of As, Ir, and Au in the magnetic separate and the correlation of their abundances with the metal content of the clasts indicate that As, Ir, and Au chiefly occur in the metal. Correlations for Zn and Sc indicate that they chiefly occur in niningerite, but a significant amount of Sc may also occur in oldhamite. The dark inclusions do not follow the As and Zn correlations, suggesting that the dark inclusions and clasts are not equilibrated with each other. Correlation of the REE and oldhamite abundances for both the clasts and dark inclusions indicates that the REE chiefly occur in oldhamite.

In view of the INAA and mineralogical evidence for non‐equilibration among the clasts and a dark inclusion (Sears et al., 1981), the similar REE patterns for clasts (3,3) and dark inclusion (5,1), and the similar mineral composition of oldhamite in clast (3,3) and dark inclusion (5,1), suggest that the oldhamite in the clasts and dark inclusions is of a common origin, which Sears et al. (1981) showed could be formed by condensation.

A Tb anomaly of a factor of 2 was found in sample (2,9 and 9,2), and a La anomaly of a factor of 2 was found in clast (3,3). The only other REE anomaly in Abee, a factor of 3.5 for Yb, was found by Nakamura and Masuda(1973). In view of the evidence for equilibration among the clasts, this anomaly must have been introduced shortly before the brecciation process and indicates that no significant reheating has occurred. This concurs with the findings of Sugiura and Strangeway (1981) and Bogard et al. (1982).
BOCAIUVA—A SILICATE‐INCLUSION BEARING IRON METEORITE RELATED TO THE EAGLE‐STATION PALLASITES
Authors: Malvin Daniel J. , Wasson John T. , Clayton Robert N. , Mayeda Toshiko K. , da Curvello Walter Silva
Published: June 2012

Bocaiuva is a unique meteorite consisting of major metal having a high Ge/Ga ratio and minor (∼ 50 mg/g) silicates. The silicates are generally chondritic and consist of major olivine (Fa.7.7) and orthopyroxene (Fs7.6) and minor plagioclase (Ab49, An49) and clinopyroxene (Fs4.5, Wo42). The low alkali content of the silicates is the only property inconsistent with a chondritic composition. Based on metal composition Bocaiuva seems distantly related to certain iron meteorites having similar Ge contents and similar Ge/Ga ratios, but detailed comparison with six such irons shows none to be closely related to Bocaiuva. Perhaps most closely related is Cold Bay, a member of the Eagle‐Station trio of pallasites, but its composition is too different to suggest formation on the same parent body. Oxygen‐isotope data show that Bocaiuva silicates are closely related to those in the Eagle‐Station pallasites and to the CO and CV chondrites. The composition and texture of the Bocaiuva metal‐silicate assembly indicate mixing in an impact event. We suggest that the Eagle‐Station pallasites were also formed by impact heating rather than by a long‐lived internal heat source.
COSMOGENIC RADIONUCLIDES AND NOBLE GASES IN THE WETHERSFIELD (1982) CHONDRITE
Authors: Evans J.C. , Reeves J.H. , Bogard D.D.
Published: June 2012

The Wethersfield (1982) chondrite was assayed for a suite of cosmogenic radionuclides shortly after fall. Data are reported for 7Be, 22Na, 26Al, 46Sc, 48V, 51Cr, 54Mn, 56Co, 57Co, and 60Co. A comparison is made with predicted results based on a scaling to the Deep River Neutron Monitor. Noble gases were also assayed in a sub‐sample. The cosmic ray exposure age is estimated to be 45 million years.
ROEDDERITE IN THE QINGZHEN (EH3) CHONDRITE
Authors: Rambaldi E.R. , Rajan R.S. , Housley R.M.
Published: June 2012

The rare mineral roedderite, (Na1.09 K0.89 Ca0.02)2.00 (Mg4.71 Fe0.27)4.98 (Si11.80 Al0.09)11.89 O30 has been found in accessory amounts in the highly unequilibrated enstatite chondrite, Qingzhen. It occurs in association with minor amounts of albite and SiO2 as inclusions within the metal or sulfide phases of metal‐sulfide assemblages. The roedderite crystals are connected through oxide and silicate veins to the surrounding matrix. The presence of glass coated vesicles on the surface of the assemblages strongly suggests that roedderite originated in the presence of a fluid phase, presumably during post‐accretional planetary processes.
THE HEDJAZ METEORITE
Authors: Fredriksson K. , Fredriksson B.J. , Kraut F.
Published: June 2012

The Hedjaz meteorite has been studied in detail and on a chemical basis, with 22.1% total Fe, 9% metallic Fe, 1.3% Ni and constant olivine composition (Fa23–24), can be classified as an L‐group chondrite. However, petrographically Hedjaz is quite hoterogeneous and contains features characteristic of types 3, 4, 5, and 6, observations that refute a petrographic type classification. Indeed, Hedjaz, as a complex breccia, exhibits no evidence of metamorphic equilibration after accretion and supports the contention that type 4 (also 5 and 6) chondrites are not derivatives of type 3 material, and that types 5 and 6 are not necessarily more “metamorphosed,” only better crystallized.
CLASSIFICATION OF TWENTY‐SIX CHONDRITES FROM ROOSEVELT COUNTY, NEW MEXICO
Authors: Sipiera Paul P. , Becker Mary J. , Kawachi Yosuke
Published: June 2012

Twenty‐six of the fifty‐seven stone meteorites listed in Huss (1979) from Roosevelt County, New Mexico, have been classified in the present study. Microprobe analyses indicate 15 H type, 9 L type and 2 LL type chondrites. Based on compositional, textural, and locational comparisons, as many as 10 chondrites may be paired to three distinct falls.
CLASSIFICATION OF A SECOND GROUP OF ORDINARY CHONDRITES FROM TEXAS
Authors: Ehlmann Arthur J. , Keil Klaus
Published: June 2012

Based on optical microscopy and electron microprobe analyses of mafic minerals, six previously undescribed or poorly known ordinary chondrites from Texas were classified into compositional groups, petrologic types, and shock facies. These meteorites are Junction, L5d; Anton, H4b; Venus, H4d; Dalhart, H5a; Rosebud, H5c; and Cranfills Gap, H6c.
Ureilite Compaction
Authors: Walker David , Agee Carl B.
Published: June 2012

Abstract— Experimental partial melting of Allende in a modest thermal gradient produces compacted crystalline residues on the cold side and silicate liquid segregations on the hot side of the gradient. The mechanism leading to this segregation is a type of zone refining: thermal migration. Chemical diffusion produces relative migration of phases along a saturation gradient induced by a temperature gradient. The compacted crystals have many features reminiscent of ureilite meteorites: olivine major element compositions, surface‐equilibrium‐controlled adcumulus textures, ripened grain sizes, virtually complete silicate melt removal, and textural elongation. Sulfide melt fails to segregate from crystals by this mechanism. If thermal migration is responsible for the textural features of ureilite compaction, then often‐assumed constraints about ambient gravity fields and cooling regimes do not apply to ureilite origins irrespective of whether the compaction is of a melting residue or a cumulus crystal pile. Certain ingrained expectations relating the geochemistry of complementary liquids to these crystals also will be unsatisfied. Because virtually any crystal consolidation regime operates through a thermal gradient, it is likely that thermal migration must play at least a small role in the process. It would be a particularly appropriate mechanism for consolidating ureilites within planetesimals undergoing vigorous primordial heating by radioactivity or electromagnetic induction—circumstances in which the efficacy of the process is not truncated by cooling. The possible existence of this mechanism does not invalidate less unusual suggestions for the origin of ureilites. However, some of the constraints on ureilite origin and complementary liquid geochemistry are now considerably relaxed.
Exposure History of H5 Chondrite Gujargaon
Authors: Bhandari N. , Padia J. T. , Rao M. N. , Shukla P. N. , Suthar K. M. , Sarafin R. , Herpers U.
Published: June 2012

Abstract— Cosmic ray produced tracks, He and Ne isotopes and radionuclides have been studied in the recently fallen H5 chondrite Gujargaon. The results indicate an exposure age of about 7 Ma. The high track production rates of 0.25 to 0.69 × 106 cm−2 Ma−1 suggest that the Gujargaon meteoroid had a small size (Re = 9–10 cm) in space and suffered 1–3 cm ablation in the atmosphere. The conclusion about the meteoroid size is supported by the low activity of neutron capture isotope 60Co and high spallogenic 22Ne/21Ne ratio of about 1.25. The data on long lived isotopes 10Be, 53Mn and 26Al are used to derive production rates of these isotopes in a rock having a radius of 9 cm and the activity levels of the short lived isotopes 22Na and 54Mn are used to estimate the effect of modulation of galactic cosmic rays at the time of solar maximum of 1982.
Origin of Petrofabrics and Magnetic Anisotropy in Ordinary Chondrites
Authors: Sneyd Deana S. , McSween Harry Y. , Sugiura Naoji , Strangway David W. , Nord Gordon L.
Published: June 2012

Abstract— Three‐dimensional finite strain and magnetic susceptibility anisotropy have been determined for 15 ordinary chondrites. The axes of strain and magnetic ellipsoids roughly correlate in both magnitude and orientation. The shapes of these ellipsoids are generally oblate spheroids that define a dominant foliation and a weak lineation. These characteristics suggest deformation involving uniaxial compaction. The degree of uniaxial deformation correlates with intensity of shock, as indicated by optical, TEM and chemical criteria. These data, plus the lack of a relationship between foliation and metamorphic history, indicate that dynamic processes, i.e., impacts, produced planar deformation fabrics in chondrites.
The Linum Chondrite
Authors: Matthes J. , Adam K.
Published: June 2012

Abstract— Based on optical microscopy and electron microprobe analysis, Linum is classified as an L6b chondrite that contains olivine (Fa24), orthopyroxene (Fs20), clinopyroxene (Wo45En47Fs8), plagioclase (An10Ab84Or6), nickel‐iron, troilite, chromite and accessory amounts of chlorapatite and whitlockite.
Shock‐implanted noble gases II: Additional experimental studies and recognition in naturally shocked terrestrial materials
Authors: Bogard Donald , Hörz Friedrich , Johnson Pratt
Published: June 2012

Abstract— Several experimentally and naturally shocked silicate samples were analyzed for noble gas contents to further characterize the phenomenon by which ambient gases can be strongly implanted into silicates by shock and to evaluate the possible importance of this process in capturing planetary atmospheres in naturally shocked samples. Gas implantation efficiency is apparently mineral independent, as mono‐mineralic powders of oligoclase, labradorite, and diopside and a powdered basalt shocked to 20 GPa show similar efficiencies. The retentivity of shock‐implanted gas during stepwise heating in the laboratory is defined in terms of two parameters: activation energy for diffusion as determined from Arrhenius plots, and the extraction temperature at which 50% of the gas is released, both of which correlate with shock pressure. These gas diffusion parameters are essentially identical for radiogenic 40Ar and shock‐implanted 40Ar in oligoclase and labradorite shocked to 20 GPa, suggesting that the two 40Ar components occupy analogous lattice sites. Our experiments indicate that gas implantation occurs through an increasing production of microcracks/defects in the lattice with increasing shock pressure. The ease of diffusive loss of implanted gas is controlled by the degree of annealing of these microcracks/defects.

Identification of a shock‐implanted component requires relatively large concentrations of implanted gas which is strongly retained (i.e., moderate activation energy) in order to separate implanted gas from surface adsorbed gases. Literature data on shocked terrestrial samples indicate only weak evidence for shock‐implanted gases, with an upper limit for 40Ar of ∼ 10−6 cm3STP/g. New analyses of shocked samples from the Wabar Crater indicate the presence of shock‐implanted Ar, having concentrations (∼ 10−4 cm3STP/g) and activation energies for diffusive loss which are essentially that expected from experimental studies. Lack of sufficient target porosity or the presence of ground water may explain the sparse evidence for shock‐implanted gas at other terrestrial craters. Although Wabar Crater may represent an unusually favorable environment on Earth for shock‐implanting gases, surfaces of other planetary bodies, such as Mars, may frequently provide such environments. Analyses of returned samples from old Martian terraines may document temporal changes in earlier atmospheric composition.