Texte über den Meteoriten, H5 (S4, W5):
THE METEORITE FROM LAKE HOUSE.C.T. Pillinger1, J.M. Pillinger1, R.C. Greenwood1, D. Johnson1,
A.G. Tindle2, A.J.T. Jull3 and M. Ashcroft4. 1PSSRI, 2EES Open
University, Milton Keynes MK7 6AA, UK. 3AMF, University of
Arizona, Tucson AZ85721, USA. 4Magna Parva Ltd., Bardon
https://docs.google.com/viewer?a=v&q=cache:4ZB-cDPPC-AJ:www.lpi.usra.edu/meetings/metsoc2011/pdf/5326.pdf+%22THE+METEORITE+FROM+LAKE+HOUSE%22&hl=de&gl=de&pid=bl&srcid=ADGEESgAQ5B6G6GknlQQ01oNH3uLPDuaVJbbAprzIN50xQbrUKPJ5yPzQGMwCtcwMs5-EfQzOB4me5-Jz49RKnFdAhC0xG_lPGdCp54so2TYR5YtDvFh8Oc05Zn3YFjK3J4dpUWcMNJo&sig=AHIEtbSqocwOpaXm35JUrPmBe4HVdDdLUwTHE METEORITE FROM LAKE HOUSE.
C.T. Pillinger1, J.M. Pillinger1, R.C. Greenwood1, D. Johnson1,
A.G. Tindle2, A.J.T. Jull3 and M. Ashcroft4. 1PSSRI, 2EES Open
University, Milton Keynes MK7 6AA, UK. 3AMF, University of
Arizona, Tucson AZ85721, USA. 4Magna Parva Ltd., Bardon
Hill, LE67 1UB, UK. c.t.pillinger@open.ac.uk
Introduction: In 1991 a very big meteorite (>60kg, dimen-
sions: diameter 50cm x height 40cm) was brought to the Natural
History Museum by the then occupier of Lake House, a country
mansion in Wiltshire, UK, associated with a large estate of the
same name. The circumstances concerning the likely origins of
this ‘find’ are dealt with in a companion abstract [1]. Our atten-
tion was attracted to it because of its proximity to Danebury Hill
(20 km east), where the only British meteorite ‘find’, collected
under controlled circumstances, was located in 1974 [2]. If the
large meteorite from Lake House turned out to be paired with the
much smaller Danebury find, then the mystery surrounding its
origin would be instantly solved.
The sample from Lake House was confirmed as a meteorite
by Robert Hutchison [3] and subsequently returned to its owners.
Our electron microprobe data from a PTS made from a chip
taken at the OU suggest it should be classified as type H5 similar
to our assignment for Danebury.
Petrography: The sample is a heavily weathered (W5) [4],
moderately shocked (S4) [5], equilibrated ordinary chondrite
(H5). Distinct chondrules are present, but these tend to have
poorly defined boundaries. Porphyritic types predominate, but
barred olivine and radial pyroxene textured chondrules are also
common. Chondrule mesostasis is recrystallised, with grain sizes
generally below 50μm. The sample is cut by a network of veins,
up to 2 mm thick, filled with secondary weathering products.
Discussion: In respect of weathering characteristics, the two
specimens are entirely different – areas in our Danebury PTS are
grade W1 and the whole specimen is no worse than W2, whereas
the meteorite from Lake House is W5. The thin section of the
latter was made from a near surface chip of the highly corroded
sample; the Danebury analyses were performed using a fresh in-
terior portion. Not wishing to have what appeared to be a very
delicate specimen disintegrate, we attempted to extract an interior
core from the larger meteorite using an experimental drill being
developed for robotic space missions. Much to our surprise pro-
longed drilling was unable to penetrate more than a millimeter
into a location where the crust appeared to be absent. In earlier
performance tests the drill had no difficulty in obtaining 1.5 cm
long cores from basalt and concrete. We conclude that the inte-
rior of the meteorite from Lake House may not be as weathered
as it appears from the outside.
Because we had obtained a very precise terrestrial weather-
ing age for Danebury, samples of the meteorite from Lake House
were removed for Accelerator Mass Spectrometry terrestrial resi-
dence dating. The first sample studied has a 14C weathering age
of 10,600 +/- 1800 years BP. A second run with a better speci-
men gave 9500 +/- 560 years. The large meteorite is clearly not
related to the small one authenticated from the archeological site
a few kilometers away. Given that it is a single stone, the meteor-
ite represents an unusually large ordinary chondrite find.
References: [1] C.T.Pillinger and J.M.Pillinger, this vol. [2]
C.T.Pillinger et al., this vol. [3] pers. comm. [4] Wlotzka F. 1993
Meteoritics 28:460. [5] Stöffler D. et al. 1991. GCA 55:3845-
3867.
EVALUATION OF VARIOUS HYPOTHESES RELATING
TO THE LOCATION OF THE FALL AND THE
SUBSEQUENT HISTORY OF A LARGE METEORITE
LATELY RECOVERED IN WILTSHIRE, UKC.T. Pillinger and J.M. Pillinger. Planetary and Space Sciences
Research Institute, The Open University, Milton Keynes, MK7
67AA, UK. c.t.pillinger@open.ac.uk
https://docs.google.com/viewer?a=v&q=cache:rbCHgijz2BwJ:www.lpi.usra.edu/meetings/metsoc2011/pdf/5317.pdf+%22EVALUATION+OF+VARIOUS+HYPOTHESES+RELATING%22&hl=de&gl=de&pid=bl&srcid=ADGEESg0Tefen6VJr5wm-QYfB_YnlFamlksXvmToI_CzW-99mYlP30SI3eifZVNmOpbfMiLwXgD-omVTX2oYow2rvxKUBoSQVK78jTo5rKZEC3QHkG4YVdEv6_kTPA6r-F7orMg5-OUf&sig=AHIEtbR2Il3BEnc_xSMeRRpU5R4DfNuutQIntroduction: A large, 60kg, weathered meteorite was
reported to have been in the UK for at least 60 years when it was
taken to the Natural History Museum, London, twenty years ago.
Previous to 1991, eye witness and photographic evidence
demonstrate that it rested for many years near to the front door of
an imposing country house in Wiltshire. It was reputed to have
been either brought to the UK or otherwise collected locally by Lt
Col Frederick George Glyn Bailey in the early twentieth century.
The descendents of FGG Bailey have made the specimen
available and encouraged a study to ascertain more information
about the meteorite before arranging for it to be on permanent
local public display.
The meteorite is described in an
accompanying abstract.
The presence of a meteorite of unknown terrestrial
provenance offers a considerable challenge. Whilst a scientific
examination [1] can offer some information, much depends on an
exhaustive examination of contemporary documents. Some while
ago we were able to piece together a detailed account of the
circumstances surrounding the fall of the Wold Cottage meteorite
to show it should not be considered as just any old ordinary
chondrite [2].
Results: The life and times of Lt Col FGG Bailey have been
researched thoroughly in order to highlight any possible links he
may have had to a meteorite find either in the UK or the rest of
the World. The meteorite is inextricably linked to the house
where it was located for so many years: Lake House. Thus the
history of the Lake House Estate, the house, its previous
occupants and their associates, including their interests and
scientific aptitude, have also been studied in an attempt to
establish the earthly provenance of the specimen.
Several hypotheses have been considered to account for the
presence of the meteorite in Wiltshire. Necessarily these
hypotheses revolve round the people who could conceivably have
had an involvement in the meteorite’s history on Earth.
Questions regarding whether they might have had the motivation,
opportunity and capability to recognize a meteorite have been
considered. Even if they did, they would have needed the
resources to move such a large stone and have the desire to
collect and display it.
A document trail has been initiated which provides new and
verifiable information about the terrestrial provenance of the
meteorite associated with Lake House. The latest findings will be
presented together with an up-to-date probability/possibility
assessment of the place of first collection and hence the site of
the fall. The work reported here may offer some pointers to
others searching archive material for reports connected to
meteorite related events.
References: [1] C.T. Pillinger et al., this volume. [2] C.T.
Pillinger and J.M. Pillinger Meteoritics and Planetary Science 31,
589-605 (1996)
Martin
Thema: Das Mysterium des 'Druiden-Meteoriten' (Gelesen 7844 mal)
