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Meteoritic event recorded in Antarctic ice

Ralph P. Harvey, Nelia W. Dunbar, William C. McIntosh, Richard P. Esser, Kuni Nishiizumi, Susan Taylor and Marc W. Caffee
Meteoritic event recorded in Antarctic ice
Geology (Boulder) (July 1998) 26 (7): 607-610


During systematic sampling of volcanic ash (tephra) layers at a well-known Antarctic meteorite collection site (the Allan Hills main ice field), a band of unusually dark and rounded (many spheroidal) particles was discovered. This debris layer (BIT-58) extends parallel to the stratigraphy of the ice established from the tephra bands, apparently marking a single depositional event. The shapes, internal texture, major element composition, and levels of cosmogenic nuclides of particles from within BIT-58 all strongly suggest that this material represents ablation debris from the passage of a large H-group ordinary chondrite. Preliminary cosmogenic isotope dating suggests an age of 2.8 Ma, implying that the East Antarctic ice sheet has been stable since that time. The relationship of the Bit-58 layer to known impact events is not clear.

ISSN: 0091-7613
EISSN: 1943-2682
Serial Title: Geology (Boulder)
Serial Volume: 26
Serial Issue: 7
Title: Meteoritic event recorded in Antarctic ice
Affiliation: Case Western Reserve University, Department of Geological Sciences, Cleveland, OH, United States
Pages: 607-610
Published: 199807
Text Language: English
Publisher: Geological Society of America (GSA), Boulder, CO, United States
References: 24
Accession Number: 1998-044251
Categories: Geochronology
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 1 table, sketch map
S77°00'00" - S76°30'00", E159°00'00" - E160°00'00"
Secondary Affiliation: New Mexico Institute of Mining and Technology, Socorro, NM, USA, United StatesUniversity of California at Berkeley, USA, United StatesCold Regions Research and Engineering Laboratory, Hanover, NH, USA, United StatesLawrence Livermore National Laboratory, Livermore, CA, USA, United States
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States
Update Code: 199817
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