| |
Nininger Moment #11
The Lafayette Meteorite
 Little is known regarding the date and time of this remarkable
fall, but the fresh appearance renders it practically certain that
it wasn't on the Earth long before its discovery and recovery before
the mechanical abuses of nature took over. A story is told that a
black student of Purdue University, Indiana reported that a number
of years ago while fishing at the edge of a little lake he was
frightened by the falling of a stone at a distance of only a few
feet from him. The stone was dug up from soft mud and found it to be
"shaped just like a corn pone" and of about the same size. For a
time he preserved the stone and later took it to the University to
shed some information on it. This report was never substantiated for
the reason that the person could not be located.
What ever its history it was first recognized by Dr. O.C Farrington
while classifying some minerals and rocks for the department of
geology in Purdue University in 1931. Up until that time the
specimen had been regarded as a glacial boulder or pebble and the
surface markings were thought to be the results of glacial scratches
due to its origin. To a student of meteorites, the Lafayette stone
at once becomes a very impressive example of the result of an
oriented flight through the atmosphere. As far as it is known to
Nininger no other meteorite records such a flight more perfectly.
Fine crinkley ridges radiate from the central point of the
spheroidal front of blackish glass. 27 thread lines were counted to
run unbroken to the periphery. Between these primaries are one to
three secondaires that start short of the central area and continue
to the periphery.
Altogether the lined surface of the stone gives the impression that
it has been formed by the cooling down from a condition in which the
surface of the entire front was in a liquid state to a temperature
below the melting point of the stone which allowed molten matter to
congeal while in the process of being swept away. The high viscosity
of the liquid resulted in the formation of more or less perfect
beads, where the sweep of the air was not too powerful. Some of the
prominence appear to be the result of unequal melting of the
underlying particles of the stone. The base of the stone represents
a totally different appearance and is flat.
The interior of the Lafayette stone constitutes one of those rare
stones that shows no metallic inclusions on a polished surface.
Three polished surfaces were examined showing no metallic inclusions
or iron nickel. The interior is an aggregate of slender prismatic
crystals of a olive drab color, with a sprinkling of lighter and
darker particles, some almost black. There is no suggestion of a
chondrite structure visible in any of the three cut surfaces and
therefore falls in the division of achondrites. Dr. W.A. Waldschmidt
of the Colorado School of Mines examined a sample of the stone and
found it to be mainly a monoclinic pyroxine, probably diopside and
therefore it should be classified with the Nakhlites of Prior.
Principal mass of the stone is about 600 grams and is preserved in
the Geological Collection of Purdue.
Nininger states that Farrington might have had information on the
details of the stone. It's not sure if he had done some
investigative work or not and had planned to write a formal paper on
the stone. Unfortunately Farrington died before writing the paper
and no documents were found in his files perhaps details lost when
he died.
Source: The Published Papers Of H.H. Nininger
By the Center for Meteorite Studies Arizona State University, Tempe,
AZ
Published originally in Popular Astronomy 1935
The Nininger Moments are articles or books written originally by
Harvey
Nininger and put into a consolidated form by Al Mitterling. Some of
the
items written in the moments might be old out dated material and the
reader is advised to keep this in mind.
--AL Mitterling
|
