Larger context for ALWAYS in Corpus brown_strip.txt DBL-CLICK WDS FOR DEF
The gallium content, however, has been enhanced five-fold.
This glass is probably formed from Libyan Desert sands by comet or stony-meteorite impact.
Nickel-iron meteorites with sufficient kinetic energy to produce large terrestrial-explosion craters may nevertheless melt only small quantities of material.
Most of the impact energy is spent in crushing and fragmentation.
When rapid quenching follows melting, impact glasses may result.
These ALWAYS contain metallic inclusions.
Impact glasses not containing elemental nickel-iron may have been produced by stony meteorites or comets.
No meteorites have ever been recovered from paleoexplosion craters, and recent craters containing impact glass have all been produced by metallic meteorites with the exception of Aouelloul crater, Adrar, Western Sahara Desert.
This crater contains impact glass with no metallic inclusions and no meteoritic material has been recovered.
(A.
J.
