GLOSSARY – F

GLOSSARY – F

by: Charles O’Dale

FELSIC (feldspar and silicon)
Silicate minerals, magmas, and rocks which have a lower percentage of the heavier elements, and are correspondingly enriched in the lighter elements, such as silicon and oxygen, aluminum, and potassium, high feldspar and silicon content.
[see – MAFIC]

FERRIC
Refers to iron with an oxidation number of +3, denoted iron(III) or Fe3+.

FERROUS
Refers to iron with an oxidation number of +2, denoted iron(II) or Fe2+.

FRACTURED ROCK
A fracture is any separation in a geologic formation, such as a joint or a fault that divides the rock into two or more pieces. One of the impact shock effects I noticed in my crater explorations was the fractured rocks around the perimeter of the structure where there should have been solid rock outcrops. Though this phenomenon IS NOT firm evidence of an impact but is a feature of impacting and would indicate that further investigation of the structure is warranted.
[see – FRACTURED ROCK]

FULLERENES
Carbon molecules of the form C60, C76, C84 … that may trap gases in their soccer ball-shaped structure. Extraterrestrial gases in fullerenes found in terrestrial rock deposits have been related with impact events, e.g., extraterrestrial helium trapped in fullerenes in the Sudbury impact structure, and extraterrestrial noble gases in fullerenes at the Permian-Triassic boundary.