Noble gas isotopic systematics of Fe–Ti–V oxide ore-related mafic–ultramafic layered intrusions in the Panxi area, China: The role of recycled oceanic crust in their petrogenesis

The Podong Permian ultramafic intrusion is only one ultramafic intrusion with massif Ni-Cu sulfide mineralization in the Pobei layered mafic-ultramafic complex, western China. It is obviously different in sulfide mineralization from the nearby coeval Poyi ultramafic intrusion with the largest disseminated Ni-Cu sulfide mineralization and mantle plume contribution (Zhang et al., 2017). The type and addition mechanism of the confirmed crustal contaminations and possible mantle plume involved in the intrusion formation require evidences from carbon and noble gas isotopic compositions. In the present study, we have measured C, He, Ne, and Ar isotopic compositions of volatiles from magmatic minerals in the Podong ultramafic intrusion. The results show that olivine, pyroxene, and plagioclase minerals in the Podong intrusion have variable δ13C of CO2 (-24.5‰ to -3.2‰). The CH4, C2H6, C3H8, and C4H10 hydrocarbon gases show normal or partial reversal distribution patterns of carbon isotope with carbon number and light δ13C1 value of CH4, indicating the hydrocarbon gases of biogenic origin. The δ13C of CO2 and CH4 suggested the magmatic volatile of the mantle mixed with the volatiles of thermogenic and crustal origins. Carbon and noble gas isotopes indicated that the Podong intrusion could have a different petrogenesis from the Poyi ultramafic intrusion. Two types of contaminated crustal materials can be identified as crustal fluids from subducted altered oceanic crust (AOC) in the lithospheric mantle source and a part of the siliceous crust. The carbon isotopes for different minerals show that magma spent some time crystallizing in a magma chamber during which assimilation of crustal material occurred. Subduction-devolatilization of altered oceanic crust could be the best mechanism that transported large proportion of ASF (air-saturated fluid) and crustal components into the mantle source. The mantle plume existing beneath the Poyi intrusion could provide less contribution of real materials of silicate and fluid components.

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Leading Interaction Components in the Structure and Reactivity of Noble Gases Compounds

Molecules ◽

10.3390/molecules25102367 ◽

2020 ◽

Vol 25 (10) ◽

pp. 2367

Author(s):

Francesca Nunzi ◽

Giacomo Pannacci ◽

Francesco Tarantelli ◽

Leonardo Belpassi ◽

David Cappelletti ◽

...

Keyword(s):

Chemical Bond ◽

Theoretical Approach ◽

Noble Gases ◽

Halogen Bond ◽

Noble Gas ◽

Anomalous Behavior ◽

Type Interaction ◽

Long Life ◽

Weak Chemical

The nature, strength, range and role of the bonds in adducts of noble gas atoms with both neutral and ionic partners have been investigated by exploiting a fine-tuned integrated phenomenological–theoretical approach. The identification of the leading interaction components in the noble gases adducts and their modeling allows the encompassing of the transitions from pure noncovalent to covalent bound aggregates and to rationalize the anomalous behavior (deviations from noncovalent type interaction) pointed out in peculiar cases. Selected adducts affected by a weak chemical bond, as those promoting the formation of the intermolecular halogen bond, are also properly rationalized. The behavior of noble gas atoms excited in their long-life metastable states, showing a strongly enhanced reactivity, has been also enclosed in the present investigation.

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Noble Gases in Terrestrial Planets: Evidence for Cometary Impacts?

International Astronomical Union Colloquium ◽

10.1017/s0252921100109789 ◽

1989 ◽

Vol 116 (1) ◽

pp. 429-437

Author(s):

Tobias Owen ◽

Akiva Bar-Nun ◽

Idit Kleinfeld

Keyword(s):

Low Temperatures ◽

Noble Gases ◽

Noble Gas ◽

Terrestrial Planets ◽

Laboratory Studies ◽

The Impact ◽

Gas Patterns ◽

Atmosphere Of Venus

AbstractThe possible role of comets in bringing volatiles to the inner planets is investigated by means of laboratory studies of the ability of ice to trap gases at low temperatures. The pattern of the heavy noble gases formed in the atmosphere of Venus can be explained by the impact of a planetesimal composed of ices formed in the range of 20 to 30 K. The noble gas patterns on Mars and Earth are less explicable by cometary bombardment alone.

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d Orbitals in the noble-gas dihalides

Canadian Journal of Chemistry ◽

10.1139/v70-455 ◽

1970 ◽

Vol 48 (17) ◽

pp. 2695-2701 ◽

Cited By ~ 8

Author(s):

R. C. Catton ◽

K. A. R. Mitchell

Keyword(s):

Noble Gas ◽

Valence Bond ◽

Ionic Character ◽

Orbital Exponent ◽

Covalent Bonds ◽

Model Calculations ◽

Pair Bonds ◽

Electron Repulsion Integrals ◽

D Orbitals

Model calculations are reported for ArF2, KrF2, XeF2, ArCl2, KrCl2, and XeCl2. The approach is to compare the energies of a number of valence-bond structures for each molecule. The calculations use Slater-type radial functions and simplify the electron repulsion integrals with the Mulliken approximation. Energies are optimized by varying the d orbital exponent and a parameter which governs the ionic character of the covalent bonds. For all the molecules it is found that the structures such as (X—M+X− + X−M+—X) and X−M2+X−, which maintain the octet rule and exclude the use of d orbitals, are less stable than the structure X—M—X which implies localized electron-pair bonds based on pd hybrids at the noble-gas atom M.Approximate molecular wave functions are obtained from a configuration interaction calculation, and the general conclusion is that the valence-bond structures incorporating d orbitals become more important as the atomic number of the central atom increases. A preliminary study of the role of the [Formula: see text] orbital is also presented, but it seems this orbital contributes mainly as a polarization effect.

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