Characterization of Highly Pathogenic Avian Influenza Virus A(H5N6), Japan, November 2016

Highly pathogenic avian influenza viruses (HPAIVs) A(H5N6) were concurrently introduced into several distant regions of Japan in November 2016. These viruses were classified into the genetic clade 2.3.4.4c and were genetically closely related to H5N6 HPAIVs recently isolated in South Korea and China. In addition, these HPAIVs showed further antigenic drift

Phase Relations in the Chromium-Poor Part of the System Diopside-Anorthite-Forsterite-MgCr2O4 in Air at 1 atm

The effect of chromium on the silicate system was studied at 1 atm by adding MgCr2O4 to the join diopside-anorthite-forsterite which is a thermal divide in the system CaO-MgO-Al2O3-SiO2. When a small amount of MgCr2O4 (0.2 - 0.5 wt%) is added to the join, the liquidus surface for spinel expands at the expense of anorthite. Thus, the assemblage diopside + forsterite + anorthite + liquid at a ternary invariant point becomes unstable and the assemblages of diopside + anorthite + spinel + liquid and diopside + forsterite + spinel + liquids appear on the liquidus surface. The points at which these assemblages are present are not "invariant" point but "piercing" point, indicating that the join diopside-anorthite-forsterite with a small amount of chromium is not thermal divide, and that the residual liquid in the crystallization can move through the join diopside-anorthite-forsterite

Effect of Oxygen Fugacity on Fassaitic Pyroxene

Stability of fassaitic pyroxene in the system CaMgSi2O6-CaFeAlSiO6-CaAl2SiO6-CaTiAl2O6 is discussed on the basis of published data. In the system CaMgSi2O6-CaFeAlSiO6 the stability field of clinopyroxene decreases with an increase in CaFeAlSiO6 content and a decrease in oxygen fugacity at constant temperature. The stability field of clinopyroxene in the system CaMgSi2O6-CaAlFeSiO6-CaAl2SiO6 is strongly influenced by oxygen fugacity at low and high pressure and decreases with respect to CaFeAlSiO6 component. Titanium content of the clinopyroxene does not seem to be affected by the change of oxygen fugacity when magnetite is stable. These data are probably useful in evaluating the condition under which natural fassaitic pyroxenes are formed

Preliminary Report on the Join CaMgSi2O6-CaFe^[3+]AlSiO6 at Low Oxygen Fugacity

The join CaMgSi2O6-CaFe^[3+]AlSiO6 was studied by the ordinary quenching method at 10^-9, 10^-10, and 10^-11 atm fO2. The solubility limit of CaFe^[3+]AlSiO6 in diopside is 20 mol.% at 1100℃ and 10^-9 atm fO2, 10 mol.% at 1100℃ and 10^-10 atm fO2 and 5 mol.% at 1100℃ and 10^-11 atm fO2. The temperature of upper limit for clinopyroxene(ss) single phase field decrease with decreasing fO2. The phase assemblages below the solidus temperatures in this join change as follows with increasing CaFe^[3+]AlSiO6: clinopyroxene(ss), clinopyroxene(ss) + melilite, clinopyroxene(ss) + melilite + spinel(ss), clinopyroxene(ss) + melilite + spinel(ss) + anorthite. The composition of clinopyroxene(ss) crystallized from the composition Di(50)FATs(50) at 1100℃, 10^-10 atm fO2 is Ca0.96 (Mg0.48Fe0.12^[2+]Fe0.26^[3+]Al0.14) (Al0.44Si1.56)O6

Study of the System CaMgSi2O6-CaFe3+AlSiO6-CaAl2SiO6-CaTiAl2O6 : II. The Join CaMgSi2O6-CaAl2SiO6-CaTiAl2O6 and its Bearing on Ca-Al-Rich Inclusions in Carbonaceous Chondrite

In the join CaMgSi2O6-CaAl2SiO6-CaTiAl2O6, forsterite, anorthite, spinel, perovskite, and clinopyroxene(ss) crystallize as the primary phases. Spinel has the widest liquidus field. Perovskite has a small liquidus field, but it is present at the subliquidus and sub solidus temperatures. Forsterite is consumed by the reaction with liquid at about 1250℃. Melilite does not have its own liquidus field, but crystallizes below the temperature of 1250°-1300℃ as a sub liquidus and subsolidus phase. Two clinopyroxenes(ss) were found in the join : one is Ti-bearing diopside(ss) and the other is Ti-pyroxene(ss) containing TiO2 up to 8.7%. The liquidus temperature of Ti-pyroxene(ss) ranges from l234℃ to 1250℃ and its liquidus field is bounded by that of forsterite, diopside(ss), perovskite, spinel and anorthite. Four univariant assemblages are encountered: spinel + anorthite + melilite + Ti-pyroxene(ss) + liquid, spinel + anorthite + melilite + perovskite + liquid, anorthite + melilite + perovskite + Ti-pyroxene(ss) + liquid, and spinel + anorthite + melilite + diopside(ss) + liquid. An invariant point spinel + anorthite + melilite + perovskite + Ti-pyroxene(ss) + liquid was confirmed at 1230℃. Two invariant points are assumed from the distribution of univariant lines: diopside(ss) + anorthite + Ti-pyroxene(ss) + perovskite + melilite + liquid, and spinel + anorthite + melilite + Ti-pyroxene(ss) + diopside(ss) + liquid. The chemical composition of the Ti-pyroxene(ss) is very close to that of clinopyroxene found in Ca-Al rich inclusions of the Allende meterorite. This clinopyroxene coexists with spinel, perovskite, melilite, and anorthite and this assemblage is the same as that of the invariant point confirmed in the present study. From the observation mentioned above, the join CaMgSi2O6–CaAl2SiO6–CaTiAl2O6 is related to the formation of the inclusions in the Allende meteorite. The bulk compositions of the Type B inclusions (Grossman, 1975) are calculated in terms of CaMgSi2O6, CaAl2SiO6, CaTiAl2O6, and MgAl2O4 (spinel), and projected to the join. The possible formation mechanism of the inclusions is discussed with reference of the crystallization of the join

Study of the System CaMgSi2O6-CaFe^[3+]AlSiO6-CaAl2SiO6-CaTiAl2O6 : III. The Join CaMgSi2O6-CaFe^[3+]AlSiO6-CaTiAl2O6 at 1 atm

The join CaMgSi2O6-CaFe^[3+]AlSiO6-CaTiAl2O6 was studied in air at 1 atm by the ordinary quenching method. Clinopyroxene(ss), forsterite, perovskite, magnetite(ss), spinel(ss), anorthite, melilite, unknown phase X and hibonite were encountered. Phase X was analysed by EPMA. At liquidus temperatures the following assemblages are confirmed: clinopyroxene(ss) + forsterite + spinel(ss) + liquid, clinopyroxene(ss) + magnetite(ss) + spinel(ss) + liquid, forsterite + perovskite + spinel(ss) + liquid, and magnetite(ss) + spinel(ss) + phase X + liquid. At subsolidus temperatures clinopyroxene(ss) single phase field extends up to 18 wt.% CaTiAl2O6, showing that the content of TiO2 in clinopyroxene(ss) increases with increasing CaFe3+ AlSiO6. Following phase assemblages were confirmed in the subsolidus regions: clinopyroxene(ss) + perovskite, clinopyroxene(ss) + perovskite + spinel(ss), clinopyroxene(ss) + perovskite + melilite (+ anorthite), clinopyroxene(ss) + perovskite + spinel(ss) + melilite + anorthite, clinopyroxene(ss) + perovskite + anorthite + spinel(ss), and clinopyroxene(ss) + perovskite + hibonite + anorthite. Even in the field of clinopyroxene(ss) + perovskite, TiO2 content in clinopyroxene(ss) continues to increase and attains up to 9.20% TiO2 and 18.57% Al2O3. An implication of the join to Ti-rich fassaitic pyroxene from the alkalic rocks is discussed

Clinopyroxenes and Spinels in the System CaMgSi2O6-CaAl2SiO6-CaCrAlSiO6 : A Preliminary Report

The system CaMgSi2O6-CaAl2SiO6-CaCrAlSiO6 has a wide liquidus field for spinel at 1 atm. In the CaMgSi2O6-rich portion, however, clinopyroxene appears as second phase and then spinel disappears to react with liquid and the phase assemblage at subsolidus temperatures becomes clinopyroxene single phase and clinopyroxene + spinel + anorthite, indicating in congruent melting of chromian pyroxene into spinel + liquid. Clinopyroxenes and spinels in the assemblage of clinopyroxene + spinel + liquid at 1 atm and higher pressure were analysed. The Cr2O3 contents of clinopyroxenes and spinels increase with increasing those of bulk compositions and attain 3.16 wt% and 48.99 wt% respectively, at the bulk composition containing 1.86 wt% Cr2O3. The Cr/Al ratios of spinels are higher than those of the bulk compositions and increase with an increase of Cr/AI ratios of the bulk compositions. Spinels and clinopyroxenes crystallizing from a composition containing 1.86 wt% Cr2O3 at 8 kbar and 1300℃ with over-saturated water contain about 70 wt% and 0.1 wt% Cr2O3, respectively. Spinels coexisting with clinopyroxene in the present system have higher Cr/Al ratios than the clinopyroxene