Using zircon saturation thermometry of source magma in strongly altered volcanic ashes

2022 ◽  
Author(s):  
Tarmo Kiipli
Keyword(s):  
Volcanic Ashes ◽  
Zircon Saturation

scholarly journals Transient rhyolite melt extraction to produce a shallow granitic pluton

2021 ◽  
Vol 7 (21) ◽  
pp. eabf0604
Author(s):  
Allen J. Schaen ◽  
Blair Schoene ◽  
Josef Dufek ◽  
Brad S. Singer ◽  
Michael P. Eddy ◽  
...  
Keyword(s):  
Time Scales ◽  
Explosive Eruptions ◽  
Upper Crust ◽  
Saturation Model ◽  
Granitic Pluton ◽  
Melt Extraction ◽  
High Silica ◽  
Melt Segregation ◽  
Zircon Saturation

Rhyolitic melt that fuels explosive eruptions often originates in the upper crust via extraction from crystal-rich sources, implying an evolutionary link between volcanism and residual plutonism. However, the time scales over which these systems evolve are mainly understood through erupted deposits, limiting confirmation of this connection. Exhumed plutons that preserve a record of high-silica melt segregation provide a critical subvolcanic perspective on rhyolite generation, permitting comparison between time scales of long-term assembly and transient melt extraction events. Here, U-Pb zircon petrochronology and 40Ar/39Ar thermochronology constrain silicic melt segregation and residual cumulate formation in a ~7 to 6 Ma, shallow (3 to 7 km depth) Andean pluton. Thermo-petrological simulations linked to a zircon saturation model map spatiotemporal melt flux distributions. Our findings suggest that ~50 km3 of rhyolitic melt was extracted in ~130 ka, transient pluton assembly that indicates the thermal viability of advanced magma differentiation in the upper crust.

Geochemical and Petrological Characterization of Ash Samples from Cascade Range Volcanoes

1971 ◽  
Vol 1 (2) ◽  
pp. 261-282 ◽  
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.

scholarly journals Contribution of volcanic ashes to the regional geochemical balance: The 2008 eruption of Chaitén volcano, Southern Chile

2012 ◽  
Vol 425 ◽  
pp. 75-88 ◽  
Author(s):  
F. Ruggieri ◽  
J.L. Fernandez-Turiel ◽  
J. Saavedra ◽  
D. Gimeno ◽  
E. Polanco ◽  
...  
Keyword(s):  
Southern Chile ◽  
Volcanic Ashes

The origins of kaolinite-rich rocks associated with coal measures in China

Clay Minerals ◽  
2001 ◽  
Vol 36 (3) ◽  
pp. 389-402 ◽  
Author(s):  
Qinfu Liu ◽  
D. A. Spears ◽  
Pengfei Zhang ◽  
Hongliang Xu
Keyword(s):  
Land Surface ◽  
Volcanic Ashes ◽  
Chinese Coal ◽  
Coal Measures ◽  
Lateral Variations

AbstractKaolinite-rich rocks are widespread in Chinese coal-bearing strata. Three main types of deposits are recognized. Those deposits identified as flint clays are several metres thick and show lateral variations in bed composition. The kaolinite is thought to have formed mainly on the adjacent landmass, but some crystallization of gels within the basin is not ruled out. Tonsteins, which formed from the in situ alteration of airfall volcanic ashes, are very common in the coal measures and are up to 0.5 m thick. Finally, kaolinite deposits are described where the development of kaolin is related to weathering of coals either close to or at the present land surface.

Review on the use of volcanic ashes for engineering applications

2018 ◽  
Vol 137 ◽  
pp. 177-190 ◽  
Author(s):  
Patrick N. Lemougna ◽  
Kai-tuo Wang ◽  
Qing Tang ◽  
A.N. Nzeukou ◽  
N. Billong ◽  
...  
Keyword(s):  
Engineering Applications ◽  
Volcanic Ashes
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