Analysis of Mount Etna’s volcanic rocks

Generalized Titanomagnetite in Hawaiian Volcanic Rocks'

A ferromagnetic oxide mineral with spinel structure was separated from Hawaiian volcanic rocks ranging from basalt to trachyte . The chemical compositions of all the specimens have been arranged on an oxygen reaction line, and can safely be interpreted as the result of a process of either oxidation or reduction of material with composition on or near this line. In the trachyte the mineral was f...

Groundwater in Sedimentary, Metamorphic and Volcanic Rocks

Isotopic analysis of mineral phases to unravel the origin of altered volcanic rocks: an example from the Leucite Hills lamproites

Study of lamproites from Leucite Hills, Wyoming, indicates that the isotopic compositions of some specimens have been modified due to the alteration and/or the presence of secondary carbonate impurities within the whole rocks. Leachate test shows that while phlogopite lamproites are not affected by secondary processes, the transitional madupitic lamproites from Middle Table Mountain and on...

Scattering matrices of volcanic ash particles of Mount St. Helens, Redoubt, and Mount Spurr Volcanoes

[1] We present measurements of the whole scattering matrix as a function of the scattering angle at a wavelength of 632.8 nm in the scattering angle range 3 –174 of randomly oriented particles taken from seven samples of volcanic ashes corresponding to four different volcanic eruptions: the 18 May 1980 Mount St. Helens eruption, the 1989–1990 Redoubt eruption, and the 18 August and 17 September...

Geochemical Character of Neogene Volcanic Rocks of the Central Beetle-

Vol ca nic rocks have formed along the length of the North Amer i can Cor dil lera dur ing the Neo gene and Qua ter nary pe ri ods. Vol ca nism of this age is dom i nantly al ka line and ex tends through out cen tral Brit ish Co lum bia and the south ern Yu kon Ter ri tory. Dis tinct prov inces of al ka line magmatism have been iden ti fied in BC, in clud ing the north ern Cor dil lera vol ca n...