diameter, was recognized as a meteor crater in June of 1937. The crater
has a level bottom, filled with clay and debris to an unknown depth,
and being situated on sloping ground, has a depth that varies from 9 to
15 m. Bedrock is partly exposed on the interior sides of the crater.
There is evidence of considerable erosion since the impact took place,
but "there appear to be no standards by which the age of this crater
can be placed between 500 and 50,000 years". It is not known exactly
how much material has been found in connection with the crater; an
estimate, based on various reports and collections, would be that at
least 500 kg of iron meteorites and perhaps 50 kg of shale balls have
been recovered. The small iron fragments, 50-200 g in size, may be
smooth wedge-shaped or elongated pieces, or they may be contorted and
twisted slugs. All have edges often knife-sharp which were produced by
the fragmentation and augmented by subsequent corrosion. A shale ball
is almost always found by digging in the surface soil. The typical
shale ball is a nodule of iron oxides with all iron corroded away.
During this process the scale first formed while still adhering to the
nucleus, fractured because the interior expanded during the rust
formation. The end result is an irregular, rounded, cavernous mass
which often has quartz and feldspar from the base rock adhering and
giving the outer layers the appearance of a bread crust or a dried up
mud bed. Summing up, we can thus conclude that about 5,000 years ago a
large iron body penetrated the atmosphere with no appreciable loss of
speed. At high altitude a minor part of the surface, probably
protuberances and other irregularities, were torn off and proceeded as
independently falling bodies. The main mass exploded on impact, created
the crater and hurled numerous fragments up to a few kilometers away.
The major part of the main mass probably vaporized or was disseminated
as minute melted globules.