Chemical Investigation of Volcanic Ashes from Showa Shinzan, Usu Volcano. I-II. I. Chemical Composition of the Volcanic. Ash.

The chemical composition of ice containing tephra (volcanic ash) layers in 22 sections of the Byrd Station ice core was examined to determine if the volcanic eruptions affected the chemical composition of the atmosphere and precipitation in the vicinity of Byrd Station. The liquid conductivity, acidity, sulfate, nitrate, aluminum, and sodium concentrations of ice samples deposited before, during, and after the deposition of the tephra layers were analyzed. Ice samples that contain tephra layers have, on average, about two times more sulfate and three to four times more aluminum than nonvolcanic ice samples. The acidity of ice samples associated with tephra layers is lowered by hydrolysis of silicate glass and minerals. Average nitrate, sodium, and conductivity are the same in all samples. Because much of the sulfur and chlorine originally associated with these eruptions may have been scavenged by ash particles, the atmospheric residence time of these volatiles would have been minimized. Therefore the eruptions probably had only a small effect on the composition of the Antarctic atmosphere and a negligible effect on local or global climate.

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Volcanic Ash as a Sustainable Binder Material: An Extensive Review

Materials ◽

10.3390/ma14051302 ◽

2021 ◽

Vol 14 (5) ◽

pp. 1302

Author(s):

Andrés Játiva ◽

Evelyn Ruales ◽

Miren Etxeberria

Keyword(s):

Chemical Composition ◽

Portland Cement ◽

Urban Areas ◽

Volcanic Ash ◽

Mechanical Performance ◽

Cement Clinker ◽

Alkali Activation ◽

Cement Production ◽

Sustainable Solutions ◽

Alkali Activated

The construction industry is affected by the constant growth in the populations of urban areas. The demand for cement production has an increasing environmental impact, and there are urgent demands for alternative sustainable solutions. Volcanic ash (VA) is an abundant low-cost material that, because of its chemical composition and amorphous atomic structure, has been considered as a suitable material to replace Portland cement clinker for use as a binder in cement production. In the last decade, there has been interest in using alkali-activated VA material as an alternative material to replace ordinary Portland cement. In this way, a valuable product may be derived from a currently under-utilized material. Additionally, alkali-activated VA-based materials may be suitable for building applications because of their good densification behaviour, mechanical properties and low porosity. This article describes the most relevant findings from researchers around the world on the role of the chemical composition and mineral contents of VA on reactivity during the alkali-activation reaction; the effect of synthesis factors, which include the concentration of the alkaline activator, the solution-to-binder ratio and the curing conditions, on the properties of alkali-activated VA-based materials; and the mechanical performance and durability properties of these materials.

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Geochemical and Petrological Characterization of Ash Samples from Cascade Range Volcanoes

Quaternary Research ◽

10.1016/0033-5894(71)90046-9 ◽

1971 ◽

Vol 1 (2) ◽

pp. 261-282 ◽

Cited By ~ 24

Author(s):

Keith Randle ◽

Gordon G. Goles ◽

Laurence R. Kittleman

Keyword(s):

Pacific Northwest ◽

Volcanic Ash ◽

Cascade Range ◽

Crystalline Material ◽

Refractive Indices ◽

Crystalline Materials ◽

The Pacific ◽

Volcanic Ashes ◽

Different Sources

Twenty-nine samples of volcanic ash from the Pacific Northwest were analyzed by instrumental neutron activation techniques, with the aim of distinguishing among ashes from different sources. Preliminary results of petrographic studies of 42 ash or pumice samples are also reported. Geochemical characteristics of Mazama ash are defined, and problems induced by winnowing of crystalline material during transport and by weathering are discussed. Contents of La, Th, and Co, and La/Yb ratios are shown to be good discriminants. Data on refractive indices and on proportions of crystalline materials also aid in distinguishing among the various volcanic ashes studied. Ash and pumice found in archaeological contexts at Fort Rock Cave, Paisley Cave, Wildcat Canyon, and Hobo Cave are all from Mount Mazama, presumably from the culminating cruption of 7000 years ago.

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