Framboidal iron oxide: Chondrite-like material from the black mat, Murray Springs, Arizona

Journal Article · Sun Jan 01 00:00:00 EST 2012 · Earth and Planetary Science Letters

DOI:https://doi.org/10.1016/j.epsl.2011.11.033· OSTI ID:1074418

Fayek, Mostafa ^[1]; Hull, Sharon ^[1]; Bergen, Laura ^[1]

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1. University of Manitoba, Canada

At the end of the Pleistocene, many large mammals became extinct in North America1. The three most common theories for this phenomenon include climate change, overkill, or disease. Recently, researchers suggested that an extraterrestrial (ET) event may have caused sudden climate change that devastated these large mammals and had profound effects on the Clovis culture2,3. Critics of the ET event or impact theory note the lack of evidence such as an impact crater, impact material, shocked quartz, or tektites4. Here we present for the first time chemical and textural evidence of impact material from the Clovis-age, Murray Springs black mat layer, Arizona, USA. The impact material contains iron oxide spherules (framboids) in a glassy iron-silica matrix, which is one indicator of a possible meteorite impact. The spherules also contain elevated concentrations of vanadium and little titanium. The chemistry of both the spherules and matrix is consistent with the chemistry of impact material associated with other meteorite impact sites and meteorite showers.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1074418
• Journal Information: Earth and Planetary Science Letters, Vol. 319-320; ISSN 0012-821X
• Country of Publication: United States
• Language: English