[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

S-A "craters" revisited


I feel rather foolish for not having checked the primary sources with
regard to study of the Sikhote-Alin meteorites. Therefor I now feel
obligated to point out that back in the 1950's, Krinov discussed and
photographed the unusual "craters" on S-A individuals.

As I was examining several Sikhote-Alin shrapnel specimens, I discovered
several "crater-like" features. I had seen the "craters" on crusted
individuals but not on shrapnel pieces.  I thought maybe my discovery would
provide more insight into this "mystery." Since I reread Gallant's
wonderful S-A article (Sky & Telescope, Feb. 1997) during Sunday breakfast,
I thought maybe I should read more by Krinov about the S-A meteorites. I
found that Krinov addressed this features in Principles of Meteoritics
(1960 Pergamon Press).

On pages 276-277 in Principles of Meteoritics, Krinov wrote:
"Small hemispherical pits are scattered upon the meteorites with diameters
measured in fractions of a millimetre and rarely reaching one or two
millimetres. Around such pits the characteristic fringe is usually
observed. These pits are formed by bubbles of gas which separate from the
meteorites at the moment of crustal formation.  At the beginning within the
hardening layer of crust there appears a bubble, which upon bursting,
leaves within the viscous layer a pit with a fringe around its edge. The
little bubbles of fine film that tear away, solidify rapidly and turn into
the tiny flasks discovered along with the globules in the soil in the
region of the fall of the Sikhote-Alin meteorite shower are a component
part of meteoric dust."

Krinov continues about these features and several other characteristic to
the S-A specimens.  On page 277, there is a photograph showing an
individual with the "pit" feature.

I guess, as the saying goes, if we don't study the past, we are doomed to
repeat it. Or at least think we discovered something new.

Martin Horejsi