Reproduction of I‐type cosmic spherules and characterization in an Fe‐Ni‐O system

2020 ◽  
Vol 55 (9) ◽  
pp. 2066-2079
Author(s):  
Huimin Shao ◽  
Hiroshi Isobe ◽  
Bingkui Miao
Keyword(s):  
Cosmic Spherules

A rare free silica-bearing micrometeorite

2021 ◽  
Author(s):  
Dafilgo Fernandes
Keyword(s):  
Mineral Assemblage ◽  
Frictional Heating ◽  
Upper Atmosphere ◽  
Carbonaceous Chondrites ◽  
Mineral Phase ◽  
Unique Type ◽  
Free Silica ◽  
System A ◽  
The Earth ◽  
Cosmic Spherules

<p>Extraterrestrial dust that reaches the Earth’s surface has shown to represent the diverse types of samples from different precursors, namely, asteroid complexes and cometary bodies from the solar system. A substantial amount of this dust that strikes the upper atmosphere is believed to have been lost due to frictional heating with air molecules. Cosmic spherules that are melted particles are some of the widely recognized micrometeorites that survived this catastrophic entry process; however, their primordial characteristics are altered from their precursors making it difficult to identify the precursors. An individual peculiar spherule MS-I35-P204 recovered from the Antarctica blue ice has been identified. The spherule has been segregated using magnetic separation method, mounted in epoxy, and examined using SEM, subsequently analysed under electron microprobe. It is surrounded by a thin magnetite rim, and also holds a single kamacite bead that protrudes out at its top. The interior mineralogy mostly constitutes of a bulk pyroxene normative glass (MnO>2wt%) with several vesicles. The rare mineral phase is a skeletal aggregate of free silica, bearing Fe nuggets embedded in a glass. An isolated narrow lath of forsterite appears to be chondritic and is observed as relict grain that is associated with an anomalous low Ca pyroxene (MnO ~1.3 wt%, FeO~13 wt%). Earlier, free silica has been reported in some chondritic meteorites particularly the Enstatite and Ordinary group, and also in some carbonaceous chondrites such as CM, CR, CH, and K. It profoundly forms a pod that encloses the ferromagnesian silicate in silica-bearing chondrules. The unusual mineral assemblage seen in this spherule thereby appears to constrain probably the unique type of its contributor which need to be studied.</p>

scholarly journals Cosmic Ray Exposure Age Determinations of Cosmic Spherules from Marine Sediments

1985 ◽  
Vol 85 ◽  
pp. 179-181
Author(s):  
Kazuo Yamakoshi
Keyword(s):  
Mass Spectrometry ◽  
Cosmic Ray ◽  
High Energy ◽  
High Energy Accelerator ◽  
Exposure Age ◽  
Cosmic Spherules ◽  
Inner Region ◽  
Exposure Ages ◽  
Cosmic Ray Exposure Age ◽  
Cosmic Ray Exposure Ages

AbstractThe cosmic ray exposure ages of deep sea metalic lie spherules were determined by various methods; low level countings (Ni-59), neutron activation analysis (Mn-53), high energy accelerator mass spectrometry (Be-10, Al-26) and mass spectrometry (K isotopes). The exposure ages of 0.3 - 50 Ma were obtained. According to Poynting-Robertson effect, the starting points (supplying sources) are located at inner region of the orbit of Saturn.

Oxygen Isotope Ratios in the Crust of Iron Meteorites

1971 ◽  
Vol 26 (9) ◽  
pp. 1485-1490 ◽  
Author(s):  
K. Heinzinger ◽  
C. Iunge ◽  
M. Schidlowski
Keyword(s):  
Oxygen Isotope ◽  
Isotope Ratio ◽  
Atmospheric Oxygen ◽  
Isotope Ratios ◽  
Oxygen Isotope Ratio ◽  
Iron Meteorites ◽  
Oxygen Isotope Ratios ◽  
Cosmic Spherules ◽  
The Difference ◽  
Extraterrestrial Material

Abstract The separation factor, aM-0= (18O/16O) magnetite/' (18O/16O) atmospheric oxygen, between the magnetite crust of iron meteorites and atmospheric oxygen has been determined to be 0.9946 ± 0.0005. It is concluded that this fractionation of the oxygen isotopes is the consequence of an equilibrium isotope effect at high temperatures. It can be assumed that this is also valid for cosmic spherules, which are mainly ablation products of iron meteorites. As these spherules are found in sediments of different geological ages, their oxygen isotope ratio can give information on the development of atmospheric oxygen. The difference of the oxygen isotope ratios between magnetite from the lithosphere and airborne magnetite can be used to distinguish between terrestrial and extraterrestrial material.

scholarly journals Major and trace element geochemistry of S-type cosmic spherules

2016 ◽  
Vol 51 (4) ◽  
pp. 718-742 ◽  
Author(s):  
N. G. Rudraswami ◽  
M. Shyam Prasad ◽  
E. V. S. S. K. Babu ◽  
T. Vijaya Kumar
Keyword(s):  
Trace Element ◽  
Trace Element Geochemistry ◽  
Element Geochemistry ◽  
Cosmic Spherules

Analyses of cosmic spherules with an X-ray microanalyser

1958 ◽  
Vol 14 (1-2) ◽  
pp. 114-117 ◽  
Author(s):  
K. Castaing ◽  
K. Fredriksson
Keyword(s):  
X Ray ◽  
Cosmic Spherules

New data on the microstructure of silicate Cosmic spherules

2012 ◽  
Vol 443 (1) ◽  
pp. 417-419
Author(s):  
N. R. Khisina ◽  
R. Wirth ◽  
D. D. Badyukov
Keyword(s):  
Cosmic Spherules

Oxygen isotopic and chemical compositions of cosmic spherules collected from the Antarctic ice sheet: Implications for their precursor materials

2005 ◽  
Vol 69 (24) ◽  
pp. 5789-5804 ◽  
Author(s):  
Toru Yada ◽  
Tomoki Nakamura ◽  
Takaaki Noguchi ◽  
Noriko Matsumoto ◽  
Minoru Kusakabe ◽  
...  
Keyword(s):  
Ice Sheet ◽  
Chemical Compositions ◽  
Antarctic Ice Sheet ◽  
Cosmic Spherules ◽  
Oxygen Isotopic ◽  
The Antarctic

scholarly journals Microtexture, nanomineralogy, and local chemistry of cryptocrystalline cosmic spherules

2016 ◽  
Vol 54 (1) ◽  
pp. 68-77 ◽  
Author(s):  
N. R. Khisina ◽  
D. D. Badyukov ◽  
R. Wirth
Keyword(s):  
Cosmic Spherules
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