Editorial for Special Issue “Mineralogy of Quartz and Silica Minerals”

Jens Götze

doi:10.3390/min8100467

Editorial for Special Issue “Mineralogy of Quartz and Silica Minerals”

Minerals ◽

10.3390/min8100467 ◽

2018 ◽

Vol 8 (10) ◽

pp. 467

Author(s):

Jens Götze

Keyword(s):

Earth’S Crust ◽

Special Issue ◽

Earth's Crust

Quartz and other silica minerals make up 12.6 wt % of the Earth’s crust and belong to the most frequent rock-forming constituents. [...]

Download Full-text

Editorial for Special Issue “Clays, Clay Minerals, and Geology”

Minerals ◽

10.3390/min11101057 ◽

2021 ◽

Vol 11 (10) ◽

pp. 1057

Author(s):

Francesco Cavalcante

Keyword(s):

Clay Minerals ◽

Sedimentary Rocks ◽

Earth’S Crust ◽

Special Issue ◽

Earth's Crust

Sedimentary rocks covering most of the Earth’s crust are mainly composed of clays, making clay minerals widespread globally. [...]

Download Full-text

Editorial for the Special Issue “The Rietveld Method in Geomaterials Characterisation”

Minerals ◽

10.3390/min11080814 ◽

2021 ◽

Vol 11 (8) ◽

pp. 814

Author(s):

Thomas N. Kerestedjian

Keyword(s):

Raw Materials ◽

Rietveld Method ◽

Earth’S Crust ◽

Fundamental Importance ◽

Special Issue ◽

Wide Range ◽

Earth's Crust

The raw materials obtained from the Earth’s crust (Geomaterials) are of fundamental importance for a wide range of industries [...]

Download Full-text

A NOTE ON THE USE OF MICROSEISMS IN DETERMINING THE SHALLOW STRUCTURES OF THE EARTH’S CRUST

Geophysics ◽

10.1190/1.1439640 ◽

1965 ◽

Vol 30 (4) ◽

pp. 665-666 ◽

Cited By ~ 85

Author(s):

Keiiti Aki

Keyword(s):

Phase Velocity ◽

Japanese Journal ◽

The United States ◽

Earth’S Crust ◽

Random Waves ◽

Frequency Range ◽

Special Issue ◽

Unknown Parameters ◽

Earth's Crust ◽

Partial Success

In the VELA UNIFORM Special Issue I of Geophysics, M. N. Toksöz presented the result of his attempt at determining the shallow structures of the earth’s crust from the phase velocity of microseisms. He stated that his attempt resulted only in partial success on account of the fact that the microseisms arrived from more than one direction at the same time with comparable strength. He also concluded that there was no way of improving the results by the use of special arrays because, according to him, there were two unknown parameters, direction and phase velocity, and without the knowledge of one the other cannot be found. I thought this problem was already solved in my paper (Aki, 1957), in which a statistical theory of determining the phase velocity of random waves was given with a successful application to microseisms in Tokyo in the frequency range of 5 to 15 cps. Since Toksöz’s conclusion might have given a pessimistic view on the use of microseisms, I feel it is necessary to report a brief summary of my old paper published in a Japanese journal which might not be well circulated in the United States.

Download Full-text