It seems like there are some unconventional places
that people can look for meteorites. For example,
ancient meteorites have been found in the carbonate
rocks of Sweden as discussed in:
Schmitz, B. Peucker-Ehrenbrink, Lindstrom, M., and
Tassinari, M., 1997, Accretion Rates of Meteorites
andCosmic Dust in the Early Ordovician. Science.
vol. 278, no. 5335, pp. 88-90.
In this paper they discussed "Abundant fossil
meteorites" that were found in "...marine,
condensed Lower Ordovician limestones..."
They note:
1. A 4-inch in diameter meteorite discovered
middle Ordovician Limestone in 1951, which was
described by Thorslund and Wickman (1981).
2. a swedish meteorite , called "Osterplana 1," which
was discovered in 5-million year older Lower Ordovician
limestone about 300 miles away from the above by Hansen
and Berstrom (1997).
Twelve more meteorites have been found at the Thorsberg
Limestone Quarry. Hansen and Berstrom (1997, pp. 3)
stated:
"A 10-foot-thick section of the
Holen ("Orthoceratite") Limestone,
of Early Middle Ordovician age, is
extracted at the Thorsberg quarry
and sawed into thin slabs that are
used for windowsills and floor tile.
Quarry workers discarded slabs with
impurities, such as the meteorites,
until Professor Maurits Lindstrom
of the University of Stockholm
alerted them to save such slabs.
The 12 specimens were recovered
between 1992 and 1996. Ten of the
specimens were recovered from a
2-foot-thick bed of limestone and
may represent a single meteorite
fall. The other three specimens were
recovered from two separate levels
above this layer. Seven of the
specimens, collected between 1993 and
1996, are from a quarried limestone
volume of no more than about 127,000
cubic feet. Most of the specimens are
now on display at the Stiftelsen Paleo
Geology Center in Lidkoping, Sweden."
The meteorites found in the Thorsberg Quarry meteorites
range in size from about 0.5 to 3.5 inches in diameter.
They have been almost completely replaced by calcite and
barite. The meteorite masses are dark reddish brown and
look like iron nodules surrounded by a zone of lighter
colored limestone.
It would be fun to look at correlative condensed sections,
in the United States and elsewhere for similar fossil
meteorites. If there was a period of increased meteorite
influx during the Ordovician, meteorites should findable
in the Untied States as well as Sweden.
Additional and Cited References
Hasen, M. C., and Bergstrom, S. M.. 1997, Ancient
meteorites. Ohio Geology, Spring 1997.
Nystrom, J. O., and Wickman, F. E., 1991, The Ordovician
chondrite from Brunflo, central Sweden; II, Secondary
minerals. Lithos. vol. 27, no. 3, pp. 167-185.
Nystrom, J. O., Lindstrom, M., and Wickman, F. E., 1988,
Discovery of a second Ordovician meteorite using
chromite as a tracer. Nature. vol. 336, pp. 572-574.
Schmitz, B., Lindstrom, M., Asaro, F., and Tassinari, M.,
1996, Geochemistry of meteorite-rich marine limestone
strata and fossil meteorites from the Lower Ordovician
at Kinnekulle, Sweden. Earth and Planetary Science
Letters. vol. 145, pp. 31-48.
Thorslund, Per, and Wickman, F. E., 1981, Middle
Ordovician chondrite in fossiliferous limestone from
Brunflo, central Sweden. Nature. vol. 289, pp. 285-286.
Thorslund, Per., Wickman, F. E., and Nystrom, J. O.,
1984, The Ordovician chondrite from Brunflo, central
Sweden, I. General description and primary minerals.
Lithos. vol. 17, pp. 87-100.
Another person, Andrew A. Sicree of the Earth and
Mineral Sciences Museum at Pennsylvania State University
is looking for meteorites in coal deposits. Web pages
and pdf files discussing his efforts can be found at:
FINDING FOSSIL METEORITES:
http://www.meteorite.com/psu_find.htm
Researchers Seek Meteorites In Coal Mines
http://www.psu.edu/ur/NEWS/SCIENCETECH/meteorite.html
POTENTIAL FOR PRESERVATION AND RECOVERY OF FOSSIL
IRON METEORITES FROM COAL, TRONA, LIMESTONE, AND
OTHER SEDIMENTARY ROCKS.
http://www.lpi.usra.edu/meetings/metsoc97/pdf/5057.pdf
There are likely various unorthodox places where
people might hunt for meteorites.
Yours,
Paul
Baton Rouge, LA
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