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Chalcophile elements in Cretaceous/Tertiary boundary sediments; terrestrial or extraterrestrial?

Johan C. Varekamp and Ellen Thomas
Chalcophile elements in Cretaceous/Tertiary boundary sediments; terrestrial or extraterrestrial? (in Geological implications of impacts of large asteroids and comets on the Earth, Leon T. Silver (editor) and Peter H. Schultz (editor))
Special Paper - Geological Society of America (1982) 190: 461-467

Abstract

Scanning electron microscope studies of particulate matter in Cretaceous/Tertiary boundary sediments reveal no common carrier phase larger than about 1 mu m for the supposedly extraterrestrial elements. Particles possibly related to an extraterrestrial impact are Fe-rich aluminosilicate spheres (similar to microtektites), Al-rich smooth spheres, K-rich feldspar spheroids, and Fe-Ti-rich particles. Mercury abundances in bulk sediment samples show no consistent enrichment pattern. Some of the supposedly extraterrestrial elements (e.g., Pt, Ni) are present within diagenetic sulfide grains. Terrestrial processes have modified the extraterrestrial element signature, and characterization of an impactor simply from sediment chemistry is erroneous. Deep-sea sediments not enriched in chalcophiles will probably provide the best clues for impactor identification.


ISSN: 0072-1077
EISSN: 2331-219X
Coden: GSAPAZ
Serial Title: Special Paper - Geological Society of America
Serial Volume: 190
Title: Chalcophile elements in Cretaceous/Tertiary boundary sediments; terrestrial or extraterrestrial?
Title: Geological implications of impacts of large asteroids and comets on the Earth
Author(s): Varekamp, Johan C.Thomas, Ellen
Author(s): Silver, Leon T.editor
Author(s): Schultz, Peter H.editor
Affiliation: Ariz. State Univ., Dep. Geol., Tempe, AZ, United States
Affiliation: Calif. Inst. Technol., Dep. Geol. Planet. Sci., Pasadena, CA, United States
Pages: 461-467
Published: 1982
Text Language: English
Publisher: Geological Society of America (GSA), Boulder, CO, United States
Meeting name: Conference on geological implications of impacts of large asteroids and comets on the Earth
Meeting location: Snowbird, UT, USA, United States
Meeting date: 19810919Oct. 19-22, 1981
References: 23
Accession Number: 1983-039500
Categories: Geochemistry of rocks, soils, and sedimentsPetrology of meteorites and tektites
Document Type: Serial Conference document
Bibliographic Level: Analytic
Illustration Description: illus. incl. 5 tables
S90°00'00" - S61°00'00", W180°00'00" - E180°00'00"
N38°06'00" - N38°06'00", W01°51'00" - W01°51'00"
N55°13'00" - N55°25'00", E12°05'60" - E12°25'00"
N42°19'60" - N43°40'00", E11°49'60" - E13°15'00"
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute.
Update Code: 1983
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