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摘要
A. 3.58 kg pallasite meteorite was found in April 2001, near the mouth of the Saugeen River on Lake Huron (44 degrees 30.385%26apos;N, 81 degrees 22.330%26apos;W) by Carl Young of London, Ontario. The specimen is in the form of an irregular triaxial ellipsoid approximately 6.8 cm x 13.4 cm x 18.1 cm. Olivine crystals are visible on the smooth exterior surface which has a thin rind of oxidized iron. The sectioned interior contains olivine crystals with a considerable range in sizes up to approximately 2.5 cm diameter. Larger crystals have angular outlines and some are fractured, although corners and small grains are rounded. Apart from the kamacite and taenite of the metal phase, only small amounts of schreibersite and troilite are present. Analysis of the metal phase by instrumental neutron activation analysis (INAA) yielded Ni 97.4 mg/g, Ga 17.2 mu g/g, Ge 77.8 mu g/g, Ir 0.137 mu g/g, and Au 2.12 mu g/g. These values lie within the defined ranges for main group pallasites, except that Ge is ca. 20% higher. Analysis by inductively coupled plasma - mass spectrometry (ICP-MS) yielded Ir 0.0755 mu g/g and Au 0.937 mu g/g, differences attributed to difference in the mass and heterogeneity of the material analyzed. Olivines were found to have a mean composition of fayalite (Fa) 12.30, within the range of compositions for main group pallasites. Although the Hopewell Mounds of south-central Ohio contain fragments of the Brenham (Kansas) pallasite that were transported there by pre-contact people and are in the same region as the Southampton meteorite find, the apparent glacial transport of the newly found pallasite together with its compositional and textural differences indicate that it is a unique meteorite and the third pallasite found in Canada. The pallasite is named after the community of Southampton in which it was found.
- 出版日期2013-1
