12.8 Ka impact confirmed by details from MUM7B site in Northern Andes, William C. Mahaney et al: Rich Murray 2013.08.14
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12.8 Ka impact confirmed by details from MUM7B site in Northern Andes, William C. Mahaney et al: Rich Murray 2013.08.14
 
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12.8 Ka impact confirmed by details from MUM7B site in Northern Andes, William C. Mahaney et al: Rich Murray 2013.08.14 August 12th, 2013 Mahaney….Again!!!: New Evidence from a Black Mat Site in the Northern Andes Supporting a Cosmic Impact 12,800 Years Ago Source:
William C. Mahaney et al, JOURNAL OF GEOLOGY Volume: 121 Issue: 4 Pages: 309-325
DOI: 10.1086/670652 Published: JUL 2013 New Evidence from a Black Mat Site in the Northern Andes Supporting a Cosmic Impact 12,800 Years Ago William C. Mahaney, arkose@...,
Leslie Keiser, Dave Krinsley, Volli Kalm, Roelf Beukens, and Allen West The Journal of Geology Vol. 121, No. 4 (July 2013), pp. 309-325 Published by: The University of Chicago Press
Article Stable URL: Abstract: Previous work has ascribed a cosmic impact origin to black, high-temperature, carbon-encrusted beds (2–3 cm thick), associated with the Younger Dryas readvance of ice at 12.8 ka during the Late Glacial in the northern Andes of Venezuela.
The evidence for this includes carbon spherules, aluminosilicate melt rocks, melted coatings of glass-like amorphous carbon, and Fe-Mn on sands and clasts derived from local felsic gneiss and granite.
These sediments have been subjected to renewed investigation using high-resolution scanning electron microscopy and energy-dispersive spectrometry, and new data show that spherules at site MUM7B exhibit unique morphologies and compositions.
Molar oxide weight percentages prove the spherules are not volcanic and show little overlap with cosmic materials. Spherule microstructures display quench melting and, thus, could not have formed from slow geological authigenic, diagenetic, or metamorphic processes.
Instead, geochemical values for the Venezuelan samples plot within the limits of impact-related materials, including tektites, ejecta, and impact spherules from a number of craters and strewnfields (cf. Chicxulub Crater, Chesapeake Bay Crater, Tunguska, Australasian tektite field, Lake Bosumtwi Crater, Ries Crater, and others).
These results are identical to previously reported spherules from the Younger Dryas boundary layer (YDB) on three continents, North America, Europe, and Asia, and the most likely origin is from a cosmic impact/airburst 12.8 ka, as previously proposed.
The MUM7B site is one of the two southernmost sites (Venezuela and Peru) in South America, thus extending the evidence supporting the YDB impact event into a new hemisphere on a new continent. PDF available at JSTOR –
if you have access through your institution. Evidence for deposition of 10 million tonnes of impact spherules across four continents 12,800 y ago, James H. Wittke et al, PNAS: Rich Murray 2013.05.22
http://rmforall.blogspot.com/2013/05/evidence-for-deposition-of-10-million.html pertinent features near Campbell Mountain, studied by Dennis Cox, by his house in Fresno, CA: Rich Murray 2011.06.27
Monday, June 27, 2011 It is easy in a few hours to locate pertinent features to the N, E,
SE, and S of Campbell Mountain, studied by Dennis Cox, a few miles NE of his house in Fresno, CA. Maybe some of us can visit for a weekend and drive around, as many intriguing sites can be found by roads.
act-event/california-melt/ \1348 19 images of Fresno mountains and rock samples Dennis Cox blog, plain text, with images of samples of magnetic black glaze on melt rocks from 13 Ka ice comet fragment extreme plasma storm geoablation
in Fresno, California: Rich Murray 2010.07.02 Friday, July 2, 2010
photo of typical air burst geoablation glaze on hard bedrock at top of
Mount Helix park, E San Diego: Rich Murray 2012.03.15
10 m broken rock hill with black glazes, W of Rancho Alegre Road, S of Coyote Trail, W of Hwy 14, S of Santa Fe, New Mexico, tour of 50 photos 1 MB size each via DropBox: Rich Murray 2011.07.28 2011.08.03
l photos 3-5 of 50
within the fellowship of service, Rich Murray
Rich Murray, MA Boston University Graduate School 1967 psychology, BS MIT 1964 history and physics, 254-A Donax Avenue, Imperial Beach, CA 91932-1918
<a href="tel:505-819-7388" value="+15058197388" target="_blank">505-819-7388 cell <a href="tel:619-623-3468" value="+16196233468" target="_blank">619-623-3468 home
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