Interaction between fumarolic gases and thermal groundwaters at Vulcano Island (Italy): evidences from chemical composition of dissolved gases in waters

Abstract The Atakor massif of the central Hoggar region of the Sahara is a complex of late Tertiary-Quaternary trachyte, phonolite, basalt, and basanite occurring chiefly as protrusions resembling eroded volcanic necks, and resting upon a basement of Suggarian (Precambrian) formations. Four types of protrusions are recognized among the nearly four hundred in the area: those with accompanying lava resting upon a bed of pyroclastics, circular or elliptical in plan; those in which the lava took the form of an oriented coulee, also resting on pyroclastics; cupola-shaped masses with some pyroclastics and little lava; and those without lava. Factors governing the form of individual protrusions include chemical composition, temperature of emission, and content of dissolved gases, as well as peculiarities of shape of the vent.

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The Origin of the Moon

Symposium - International Astronomical Union ◽

10.1017/s0074180900178209 ◽

1962 ◽

Vol 14 ◽

pp. 149-155 ◽

Cited By ~ 1

Author(s):

E. L. Ruskol

Keyword(s):

Chemical Composition ◽

Solar System ◽

The Moon ◽

The Earth ◽

The Difference ◽

Origin Of The Moon

The difference between average densities of the Moon and Earth was interpreted in the preceding report by Professor H. Urey as indicating a difference in their chemical composition. Therefore, Urey assumes the Moon's formation to have taken place far away from the Earth, under conditions differing substantially from the conditions of Earth's formation. In such a case, the Earth should have captured the Moon. As is admitted by Professor Urey himself, such a capture is a very improbable event. In addition, an assumption that the “lunar” dimensions were representative of protoplanetary bodies in the entire solar system encounters great difficulties.

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On the Inhomogeneity of Chemical Composition over the Surface of 21 Per

International Astronomical Union Colloquium ◽

10.1017/s0252921100080659 ◽

1976 ◽

Vol 32 ◽

pp. 343-349

Author(s):

Yu.V. Glagolevsky ◽

K.I. Kozlova ◽

V.S. Lebedev ◽

N.S. Polosukhina

Keyword(s):

Chemical Composition ◽

Spectral Line ◽

Variable Star ◽

Radial Velocities ◽

Crimean Astrophysical Observatory ◽

Line Intensities ◽

Magnetic Variable

SummaryThe magnetic variable star 21 Per has been studied from 4 and 8 Å/mm spectra obtained with the 2.6 - meter reflector of the Crimean Astrophysical Observatory. Spectral line intensities (Wλ) and radial velocities (Vr) have been measured.

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Structural Studies on Mitotic Spindle Fibres

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100070345 ◽

1978 ◽

Vol 36 (3) ◽

pp. 615-626

Author(s):

J.R. Mcintosh

Keyword(s):

Chemical Composition ◽

Mitotic Spindle ◽

Structural Studies ◽

Mitotic Apparatus ◽

Chemical Studies ◽

Medical Interest ◽

Spindle Fibres

The mitotic apparatus is a structure of obvious biological and medical interest, but it has proved to be a difficult cellular machine to understand. The chemical composition of the spindle is only slightly elucidated, largely because of the difficulties in preparing useful isolates of the structure. Chemical studies of the mitotic spindle have been reviewed elsewhere (Mcintosh, 1977), and will not be discussed further here. One would think that structural studies on the mitotic apparatus (MA) in situ would be straightforward, but even with this approach there is some disagreement in the results obtained with various methods and by different investigators. In this paper I will review briefly the approaches which have been used in structural studies of the MA, pointing out the strengths and problems of each approach. I will summarize the principal findings of the different methods, and identify what seem to be fruitful avenues for further work.

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