Identification of the origin of silicate, magnetic and glass spherules from trace elemental abundances by INAA

1987 ◽  
Vol 114 (2) ◽  
pp. 329-335 ◽  
Author(s):  
S. L. Ma ◽  
C. F. Chai ◽  
X. Y. Mao ◽  
H. C. Peng ◽  
K. Lu ◽  
...  
Keyword(s):  
Elemental Abundances ◽  
Trace Elemental

Trace Elemental Analysis Technologies using Atmospheric Plasma Sources

2010 ◽  
Vol 130 (10) ◽  
pp. 955-962 ◽  
Author(s):  
Kaori Shigeta ◽  
Yoichi Nagata ◽  
Takahiro Iwai ◽  
Hidekazu Miyahara ◽  
Akitoshi Okino
Keyword(s):  
Elemental Analysis ◽  
Atmospheric Plasma ◽  
Trace Elemental Analysis ◽  
Plasma Sources ◽  
Trace Elemental

Elemental Abundances in Five Stars in M54, A Globular Cluster Associated with the Sagittarius Galaxy

1999 ◽  
Vol 118 (3) ◽  
pp. 1245-1251 ◽  
Author(s):  
Jeffery A. Brown ◽  
George Wallerstein ◽  
Guillermo Gonzalez
Keyword(s):  
Globular Cluster ◽  
Elemental Abundances

Elemental Abundances in Evolved Supergiants. II. The Young Clusters [CLC]h[/CLC] and χ Persei

2000 ◽  
Vol 119 (4) ◽  
pp. 1839-1847 ◽  
Author(s):  
Guillermo Gonzalez ◽  
George Wallerstein
Keyword(s):  
Elemental Abundances ◽  
Young Clusters

scholarly journals Obsidian pyroclasts in the Yellowstone-Snake River Plain ignimbrites are dominantly juvenile in origin

2021 ◽  
Vol 83 (4) ◽  
Author(s):  
L. R. Monnereau ◽  
B. S. Ellis ◽  
D. Szymanowski ◽  
O. Bachmann ◽  
M. Guillong
Keyword(s):  
Glass Composition ◽  
Snake River Plain ◽  
Explosive Eruptions ◽  
Snake River ◽  
Pyroclastic Deposits ◽  
Volcanic Conduit ◽  
Trace Elemental ◽  
Multiple Cycles ◽  
River Plain ◽  
Glass Compositions

AbstractDense, glassy pyroclasts found in products of explosive eruptions are commonly employed to investigate volcanic conduit processes through measurement of their volatile inventories. This approach rests upon the tacit assumption that the obsidian clasts are juvenile, that is, genetically related to the erupting magma. Pyroclastic deposits within the Yellowstone-Snake River Plain province almost without exception contain dense, glassy clasts, previously interpreted as hyaloclastite, while other lithologies, including crystallised rhyolite, are extremely rare. We investigate the origin of these dense, glassy clasts from a coupled geochemical and textural perspective combining literature data and case studies from Cougar Point Tuff XIII, Wolverine Creek Tuff, and Mesa Falls Tuff spanning 10 My of silicic volcanism. These results indicate that the trace elemental compositions of the dense glasses mostly overlap with the vesiculated component of each deposit, while being distinct from nearby units, thus indicating that dense glasses are juvenile. Textural complexity of the dense clasts varies across our examples. Cougar Point Tuff XIII contains a remarkable diversity of clast appearances with the same glass composition including obsidian-within-obsidian clasts. Mesa Falls Tuff contains clasts with the same glass compositions but with stark variations in phenocryst content (0 to 45%). Cumulatively, our results support a model where most dense, glassy clasts reflect conduit material that passed through multiple cycles of fracturing and sintering with concurrent mixing of glass and various crystal components. This is in contrast to previous interpretations of these clasts as entrained hyaloclastite and relaxes the requirement for water-magma interaction within the eruptive centres of the Yellowstone-Snake River Plain province.

scholarly journals The bimodal [Mg/Fe] versus [Fe/H] bulge sequence as revealed by APOGEE DR14

2019 ◽  
Vol 626 ◽  
pp. A16 ◽  
Author(s):  
A. Rojas-Arriagada ◽  
M. Zoccali ◽  
M. Schultheis ◽  
A. Recio-Blanco ◽  
G. Zasowski ◽  
...  
Keyword(s):  
Fundamental Parameters ◽  
Elemental Abundances ◽  
Data Release ◽  
Bulge Region ◽  
Solar Metallicity ◽  
Inner Region ◽  
Clean Sample ◽  
Metallicity Distribution ◽  
Single Sequence

Context. The Galactic bulge has a bimodal metallicity distribution function: different kinematic, spatial, and, potentially, age distributions characterize the metal-poor and metal-rich components. Despite this observed dichotomy, which argues for different formation channels for those stars, the distribution of bulge stars in the α-abundance versus metallicity plane has been found so far to be a rather smooth single sequence. Aims. We use data from the fourteenth data release of the APOGEE spectroscopic survey (DR14) to investigate the distribution in the Mg abundance (as tracer of the α-elements)-versus-metallicity plane of a sample of stars selected to be in the inner region of the bulge. Methods. A clean sample has been selected from the DR14 using a set of data- and pipeline-flags to ensure the quality of their fundamental parameters and elemental abundances. An additional selection made use of computed spectro-photometric distances to select a sample of likely bulge stars as those with RGC ≤ 3.5 kpc. We adopt magnesium abundance as an α-abundance proxy for our clean sample as it has been proven to be the most accurate α-element as determined by ASPCAP, the pipeline for data products from APOGEE spectra. Results. From the distribution of our bulge sample in the [Mg/Fe]-versus-[Fe/H] plane, we found that the sequence is bimodal. This bimodality is given by the presence of a low-Mg sequence of stars parallel to the main high-Mg sequence over a range of ∼0.5 dex around solar metallicity. The two sequences merge above [Fe/H] ∼ 0.15 dex into a single sequence whose dispersion in [Mg/Fe] is larger than either of the two sequences visible at lower metallicity. This result is confirmed when we consider stars in our sample that are inside the bulge region according to trustworthy Gaia DR2 distances.

Trace elemental fingerprinting of Ayurvedic formulation Nishakatakadi using XRF and NAA

2021 ◽  
Vol 328 (1) ◽  
pp. 435-446
Author(s):  
Salma Ibrahim ◽  
M. M. Musthafa ◽  
M. Mohamed Aslam ◽  
K. M. Abdurahman ◽  
M. Sudarshan ◽  
...  
Keyword(s):  
Trace Elemental ◽  
Elemental Fingerprinting

scholarly journals ASCA observations of clusters of galaxies

1996 ◽  
Vol 175 ◽  
pp. 363-366
Author(s):  
Koujun Yamashita
Keyword(s):  
High Resolution Spectroscopy ◽  
Atomic Processes ◽  
Spectral Fitting ◽  
Elemental Abundances ◽  
Hot Plasma ◽  
Emission Models ◽  
Formation And Evolution ◽  
Collisional Ionization ◽  
Intracluster Gas

X-ray emissions from clusters are most likely originated from a thin hot plasma in a collisional ionization equilibrium. The optical depth of continuum component is order of 10–3, whereas that of emission lines is around unity. Present emission models used for spectral fitting can not estimate this effect, so that the determination of elemental abundances seems to include large uncertainty. The high resolution spectroscopy with ASCA gives a clue to investigate the physical state of hot intracluster gas and a impact to reconsider the basic atomic processes. This is important issue to deeply understand the structure, formation and evolution of clusters, and the origin of intracluster gas.

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