Über die leichten Edelgase in dem Chondriten Kirin / About the Light-weight Noble Gases in the Kirin H-chondrites

1980 ◽  
Vol 35 (1) ◽  
pp. 37-43
Author(s):  
F. Begemann ◽  
O. Braun ◽  
H. W. Weber
Keyword(s):  
Noble Gas ◽  
Cosmic Ray ◽  
Parent Body ◽  
Cosmogenic Nuclides ◽  
Gas Release ◽  
Catastrophic Event ◽  
H Chondrites ◽  
Release Curve ◽  
The Difference ◽  
Strong Diffusion

Results are reported for the contents of He, Ne, and Ar of three different specimens from the Kirin H-chondrite which, with a recovered weight of about 4000 kg, is the largest known stone meteorite. The concentrations of spallogenic gases cover a range of more than a factor of two; bulk samples with ratios 3He/21Ne ≲ 2 and a FeNi nugget with 3He/38Ar = 8.8 ± 0.6 indicate strong diffusion losses of 3He from the silicates and of tritium from the metal. - Radiogenic 4He and 40Ar have been affected by diffusion, too, resulting in discordant U/Th-4He- and 40K-40Argas retention ages as well as distinctly different ages for different samples. Stepwise heating experiments show the main release of 4He and 40Ar to occur at around 800 °C and the difference in the gas contents to be due to differences in the low-temperature part of the gas release curve. - An attempt is made to account for the observed positive correlation between the concentrations of spallogenic and radiogenic noble gas nuclides. Either the diffusion losses of both have occured at the same time which requires a (quasi-)continuous loss due to a small perihelion distance or a catastrophic event late during the cosmic ray exposure history, but more than about 105 years before the fall of the meteorite. As an alternative model it is suggested that the Kirin meteoroid was hot upon the ejection from its parent body. As the subsequent cooling rate of the meteoroid is smallest in the interior the diffusion losses of radiogenic 4He and 40Ar will be largest where the production rate of the cosmogenic nuclides is smallest.

Cosmogenic Nuclides

2020 ◽  
Author(s):  
Rainer Wieler
Keyword(s):  
Noble Gas ◽  
Cosmic Ray ◽  
Parent Body ◽  
Cosmogenic Nuclides ◽  
Cosmogenic Nuclide ◽  
Production Models ◽  
History Of ◽  
Noble Gas Isotopes ◽  
Exposure Ages

Cosmogenic nuclides are produced by the interaction of energetic elementary particles of galactic (or solar) cosmic radiation and their secondaries with atomic nuclei in extraterrestrial or terrestrial material. Cosmogenic nuclides usually are observable only for some noble gas isotopes, whose natural abundances in the targets of interest are exceedingly low; some radioactive isotopes with half-lives mostly in the million-year range; and a few stable nuclides of elements, such as Gd and Sm, whose abundance is sizably modified by reactions with low energy secondary cosmic ray neutrons. In solid matter, the mean attenuation length of galactic cosmic ray protons is on the order of 50 cm. Therefore, cosmogenic nuclides are a major tool in studying the history of small objects in space and of matter near the surfaces of larger parent bodies. A classical application is to measure “exposure ages” of meteorites, namely the time they spent as a small body in interplanetary space. In some cases, also the previous history of the future meteorite in its parent-body regolith can be constrained. Such information helps to understand delivery mechanisms of meteorites from their parent asteroids or parent planets and to constrain the number of ejection events responsible for the collected meteorites. Cosmogenic nuclides in lunar samples from known depths of up to ~2 m serve to study the deposition and mixing history of the lunar regolith over hundreds of millions of years, as well as to calibrate nuclide production models. Present and future sample return missions rely on cosmogenic nuclide measurements as important tools to constrain the sample’s exposure history or loss rates of their parent body surfaces to space. The first data from cosmogenic noble gas isotopes measured on the surface of Mars demonstrate that the exposure and erosional history of planetary bodies can be obtained by in-situ analyses. For the foreseeable future, exposure ages of presolar grains in meteorites are presumably the only means to quantitatively constrain their presolar history. In some cases, irradiation effects of energetic particles from the early sun can be detected in early solar system condensates, confirming that the early sun was likely much more active than today, as expected from observations of young stars. The ever-increasing precision of isotope analyses also reveals tiny isotopic anomalies induced by cosmic-ray effects in several elements of interest in cosmochemistry, which need to be recognized and corrected for. Cosmogenic nuclide studies rely on the knowledge of their production rates, which depend on the elemental composition of a sample and its “shielding” during irradiation, that is, its position within an irradiated object and for meteorites their preatmospheric size. The physics of cosmogenic nuclide production is basically well understood and has led to sophisticated production models. They are most successful if a sample’s shielding can be constrained by the analyses of several cosmogenic nuclides with different depth dependencies of their production rates. Cosmogenic nuclides are also an important tool in Earth Sciences. The foremost example is 14C produced in the atmosphere and incorporated into organic material, which is used for dating. Cosmogenic radionuclides and noble gases produced in-situ in near surface samples, mostly by secondary cosmic-ray neutrons, are an important tool in quantitative geomorphology and related fields.

scholarly journals A Petrologic and Noble Gas Isotopic Study of New Basaltic Eucrite Grove Mountains 13001 from Antarctica

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 279
Author(s):  
Chuantong Zhang ◽  
Bingkui Miao ◽  
Huaiyu He ◽  
Hongyi Chen ◽  
P. M. Ranjith ◽  
...  
Keyword(s):  
Noble Gas ◽  
Research Work ◽  
Cosmic Ray ◽  
Parent Body ◽  
Chemical Compositions ◽  
Isotopic Study ◽  
Impact Processes ◽  
Antarctic Research ◽  
Formation And Evolution ◽  
Grove Mountains

Howardite-Eucrite-Diogenite (HED) meteorite clan is a potential group of planetary materials which provides significant clues to understand the formation and evolution of the solar system. Grove Mountains (GRV) 13001 is a new member of HED meteorite, recovered from the Grove Mountains of Antarctica by the Chinese National Antarctic Research Expedition. This research work presents a comprehensive study of the petrology and mineralogy, chemical composition, noble gas isotopes, cosmic-ray exposure (CRE) age and nominal gas retention age for the meteorite GRV 13001. The output data indicate that GRV 13001 is a monomict basaltic eucrite with typical ophitic/subophitic texture, and it consists mainly of low-Ca pyroxene and plagioclase with normal eucritic chemical compositions. The noble gas based CRE age of the GRV 13001 is approximately 29.9 ± 3.0 Ma, which deviates from the major impact events or periods on the HED parent body. Additionally, the U,Th-4He and 40K-40Ar gas retention ages of this meteorite are ~2.5 to 4.0 Ga and ~3.6 to 4.1 Ga, respectively. Based on the noble gases isotopes and the corresponding ages, GRV 13001 may have experienced intense impact processes during brecciation, and weak thermal event after the ejection event at approximately 30 Ma.

scholarly journals Noble Gas Record of Japanese Chondrites

1989 ◽  
Vol 44 (10) ◽  
pp. 935-944
Author(s):  
Nobuo Takaoka ◽  
Masako Shima ◽  
Fumitaka Wakabayashi
Keyword(s):  
Noble Gas ◽  
Cosmic Ray ◽  
Ordinary Chondrites ◽  
Isotopic Signatures ◽  
Shock Heating ◽  
H Chondrites ◽  
Gas Loss ◽  
Exposure Ages ◽  
Cosmic Ray Exposure Ages ◽  
Gas Component

Abstract Concentrations and isotopic ratios of noble gases are reported for nineteen Japanese chondrites. Among those, Nio (H3-4) is a solar-gas-rich meteorite.U/Th - He ages are younger than K - Ar ages for all meteorites studied. Six of the nine L-chondrites give significantly young K-Ar ages, suggesting gas loss by impact shock heating. The remaining three L-chondrites and seven of the ten H-chondrites have K-Ar ages older than 4 Ga. The L-chondrite Nogata and the H-chondrites Numakai, Ogi and Higashi-Koen have concordant ages.Cosmic-ray exposure ages for six of the H-chondrites show clustering around the 6-Myr peak in the distribution of exposure ages, while those for the L-chondrites, ranging from 8.2 to 64 Myr, do not show clustering.Fukutomi (L4) contains trapped 36Ar in excess, 3.5 times enriched compared to the highest value so far reported for type-4 ordinary chondrites except solar-gas-rich chondrites. The 36Ar/132Xe and 84Kr/132Xe ratios fit along a mixing line between a planetary and a sub-solar (or argon-rich) component found in separates of E-chondrites [43], The Xe isotopic composition is identical with that in Abee and Kenna. The isotopic signatures suggest that this meteorite may contain mineral fragments bearing the noble gas component found in E-chondrites or ureilites. Fukutomi also contains 80Kr, 82Kr and 128Xe produced by epithermal neutron captures on 79Kr, 81Kr and 127I, respectively. From the neutron-produced Kr, the preatmospheric minimum radius is estimated to be 20 cm with an assumption of a spherical meteoroid.

scholarly journals The Kumtag Meteorite Strewn Field

2020 ◽  
Author(s):  
Ke Du ◽  
Shijie Li ◽  
Ingo Leya ◽  
Thomas Smith ◽  
Dongliang Zhang ◽  
...  
Keyword(s):  
Total Mass ◽  
Cosmic Ray ◽  
Parent Body ◽  
Ordinary Chondrite ◽  
Impact Event ◽  
Exposure Age ◽  
H Chondrites ◽  
Cosmic Ray Exposure Age

Abstract The Kumtag meteorite strewn field was found in the Kumtag desert, 132 kilometers south of Hami city in the Xinjiang province, China. It is an ellipse of 2.5×7.9 km, with a long axis extending along the northeast-southwest direction. The largest individual meteorite of the strewn field weights about 10 kg; the smallest individual has as mass of only 27 g. In total more than 100 individuals with a total mass of more than 180 kg were collected. The Kumtag meteoroid entered the atmosphere in the direction Northeast-Southwest. All meteorites collected in this strewn field are samples from the same unique meteorite shower. The Kumtag meteorite is an H5 ordinary chondrite with a shock stage S2, and a weathering grade W2. The cosmic ray exposure age of Kumtag is 6.7± 0.8 Ma, which is rather typical for H chondrites and which indicates that Kumtag was derived from the massive impact event on its parent body ~7 Ma ago. A significant He amount has been released during certain unknown processe(s) before the Kumtag meteorite was ejected from its parent body.

scholarly journals On the Proton-Bound Noble Gas Dimers (Ng-H-Ng)+ and (Ng-H-Ng')+ (Ng, Ng'= He-Xe): Relationships betweenStructure, Stability, and Bonding Character

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1305
Author(s):  
Stefano Borocci ◽  
Felice Grandinetti ◽  
Nico Sanna
Keyword(s):  
Theoretical Calculations ◽  
Noble Gas ◽  
Structure Stability ◽  
Covalent Bonds ◽  
Dissociation Energies ◽  
Non Covalent Interactions ◽  
The Difference ◽  
Noble Gas Dimers ◽  
Covalent Interactions ◽  
Cluster Level

The structure, stability, and bonding character of fifteen (Ng-H-Ng)+ and (Ng-H-Ng')+ (Ng, Ng' = He-Xe) compounds were explored by theoretical calculations performed at the coupled cluster level of theory. The nature of the stabilizing interactions was, in particular, assayed using a method recently proposed by the authors to classify the chemical bonds involving the noble-gas atoms. The bond distances and dissociation energies of the investigated ions fall in rather large intervals, and follow regular periodic trends, clearly referable to the difference between the proton affinity (PA) of the various Ng and Ng'. These variations are nicely correlated with the bonding situation of the (Ng-H-Ng)+ and (Ng-H-Ng')+. The Ng-H and Ng'-H contacts range, in fact, between strong covalent bonds to weak, non-covalent interactions, and their regular variability clearly illustrates the peculiar capability of the noble gases to undergo interactions covering the entire spectrum of the chemical bond.

scholarly journals Gamma Flux in 14C Laboratories

Radiocarbon ◽  
1992 ◽  
Vol 34 (3) ◽  
pp. 428-430 ◽  
Author(s):  
Páll Theodórsson ◽  
Lauri Kaihola ◽  
H. H. Loosli ◽  
José M. Rodríguez
Keyword(s):  
Gamma Radiation ◽  
Radiocarbon Dating ◽  
Radiation Flux ◽  
Cosmic Ray ◽  
Cosmogenic Nuclides ◽  
Collaborative Group ◽  
Counting System ◽  
Γ Radiation ◽  
Gamma Flux ◽  
Anticoincidence Counting

An informal collaborative group of radiocarbon dating laboratories, the Low-Level Club, has been established to measure the gamma radiation flux and to test the efficiency of the anticoincidence counting system in laboratories with a NaI detector unit. The detector will record gamma radiation from cosmogenic nuclides, muons and secondary γ radiation formed in the passive shield by charged cosmic-ray particles. We present here the first phase of this work.

Carbonaceous chondrite meteorites experienced fluid flow within the past million years

Science ◽  
2021 ◽  
Vol 371 (6525) ◽  
pp. 164-167
Author(s):  
Simon Turner ◽  
Lucy McGee ◽  
Munir Humayun ◽  
John Creech ◽  
Brigitte Zanda
Keyword(s):  
Fluid Flow ◽  
Solar System ◽  
Cosmic Ray ◽  
Parent Body ◽  
Uranium Isotopes ◽  
The Past ◽  
Uranium Ion ◽  
Impact Heating ◽  
The Impact ◽  
Cosmic Ray Exposure Age

Carbonaceous chondritic meteorites are primordial Solar System materials and a source of water delivery to Earth. Fluid flow on the parent bodies of these meteorites is known to have occurred very early in Solar System history (first <4 million years). We analyze short-lived uranium isotopes in carbonaceous chondrites, finding excesses of 234-uranium over 238-uranium and 238-uranium over 230-thorium. These indicate that the fluid-mobile uranium ion U6+ moved within the past few 100,000 years. In some meteorites, this time scale is less than the cosmic-ray exposure age, which measures when they were ejected from their parent body into space. Fluid flow occurred after melting of ice, potentially by impact heating, solar heating, or atmospheric ablation. We favor the impact heating hypothesis, which implies that the parent bodies still contain ice.

Baryon production at LHC experiments: average pt of hyperons versus energy

2020 ◽  
Vol 35 (13) ◽  
pp. 2050067
Author(s):  
Olga I. Piskounova
Keyword(s):  
Cosmic Ray ◽  
String Model ◽  
Baryon Production ◽  
Proton Antiproton ◽  
Proton Proton ◽  
Low Energies ◽  
Momentum Spectra ◽  
Transverse Momentum Spectra ◽  
The Difference ◽  
Proton Proton Collisions

This paper examines the transverse momentum spectra of baryons in the multiparticle production at modern colliders in the frameworks of Quark–Gluon String Model (QGSM). It discusses: (i) the difference in [Formula: see text] hyperon spectra at proton–antiproton versus proton–proton reactions on previous colliders; (ii) the difference in hyperon spectra between the experiments on colliders of low energies and the results from modern machines; (iii) the growth of average transverse momenta of [Formula: see text] hyperon with the energies of proton–proton collisions up to [Formula: see text] TeV of LHC experiments. This analysis of baryon spectra led to the following conclusions. First, the fragmentation of antidiquark–diquark side of one-pomeron diagram makes the major contribution to baryon production spectra in the asymmetric [Formula: see text] reaction. Second, the average [Formula: see text]’s of hyperons in [Formula: see text] collisions steadily grow with energy in the range from [Formula: see text] GeV to 7 TeV. The additional conclusion is the following: since no dramatic changes have been seen in the characteristics of baryon production, the hadroproduction processes do not cause the “knee” in the cosmic ray proton spectra at the energies between Tevatron collider and LHC.

scholarly journals Noble gas record and cosmic-ray exposure history of the new CO3 chondrite Moss--Comparison with Lancé and other CO chondrite falls

2010 ◽  
Vol 45 (8) ◽  
pp. 1380-1391 ◽  
Author(s):  
Rainer BARTOSCHEWITZ ◽  
Ulrich OTT ◽  
Luitgard FRANKE ◽  
Siegfried HERRMANN ◽  
Yukio YAMAMOTO ◽  
...  
Keyword(s):  
Noble Gas ◽  
Cosmic Ray ◽  
History Of ◽  
Exposure History

scholarly journals The energy loss of cosmic ray particles in metal plates

1937 ◽  
Vol 160 (901) ◽  
pp. 304-323 ◽  
Keyword(s):  
Magnetic Field ◽  
Energy Loss ◽  
Cosmic Ray ◽  
Metal Plate ◽  
Usual Method ◽  
Cloud Chamber ◽  
Zero Magnetic Field ◽  
Metal Plates ◽  
Curvature Measurements ◽  
The Difference

Measurements have been made of the energy loss of cosmic ray particles in metal plates, making use of a counter controlled cloud chamber in a magnetic field (Blackett 1936). A metal plate was placed across the centre of the chamber and the energy loss of a ray was deduced from the difference of the curvature of a track above and below the plate. Energy loss measurements by this method have been carried out by Anderson and Neddermeyer (1936) up to an energy of about 4 x 10 8 e-volts and recently by Crussard and Leprince-Ringuet (1937) up to an energy of 1·2 x 10 9 e-volts. The curvature measurements were made mainly by means of the optical null method recently described (Blackett 1937 a ) and this proved invaluable. It would have been hard to obtain so high an accuracy by the usual method of measuring coordinates. The curvature corrections to be applied to the measured curvatures were obtained by measurements on tracks in zero magnetic field (Blackett and Brode 1936). Two separate distortion curves were required, one for the top and one for the bottom of the chamber.

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