GLOSSARY – N-O
by: Charles O’Dale
A sheet of rock that has moved sideways over neighboring strata as a result of an overthrust or folding.
Cloud of comets hypothesized to be the source of the long-period comets. Periodical disturbance of the Oort cloud has been proposed to be related with a disputed periodical increase of cometary impacts on the Earth (Shiva theory).
[see – KUIPER BELT]
2.4 billion years ago, the irreversible increase in the oxygen content of Earth’s near-surface atmosphere. Not only did it affect biological survival on our planet, but it also resulted in an extraordinary increase in mineral diversification.