5. Corroboration of Early Discoveries of Extraterrestrial Tin Particles in Polar Ice

     Tin found in YD boundary samples. Another very important finding that the YDB group announced at the 2007 Acapulco AGU meeting is their discovery of large concentrations of tin at the YD boundary. Darrah, et al. (2007) conducted SEM analysis of magnetic separates taken from the 12,950 years b2k boundary at several C-14 dated Clovis sites across the U.S. They found that these separates contained ET markers such as platinum (Pt) and nickel (Ni), but also certain of these particles were found to contain ET indicators in association with volatile metals such as tin (Sn) and copper (Cu). Metal combinations found included Fe-Ni, Cu-Ni, Fe-Sn-Ni, with particles in various examples containing 25 - 28% Sn, 12 - 90% Cu, 1 - 11% Ni, and 5 - 98% Pt. The grains were found to be in a metallic state and relatively unoxidized.
     Findings of the 1983 Portland State University study. As mentioned earlier, in the early 80's at Portland State University I had conducted neutron activation analysis of polar ice dust as a test of my superwave hypothesis; see figures 5 and 6. As disclosed in my 1983 dissertation and in subsequent publications, out of the eight Greenland ice samples I tested that ranged in age from 38.7 to 78.5 kyrs b2k, six contained high concentrations of ET metallic indicators such as Ir and Ni, and four also contained high concentrations of volatile metals such as Sn, Sb, and Ag. In fact one 50,000 year old sample was found to consist of 60±15% tin (LaViolette, 1983a, 1983c). The tin and iridium abundances found in these samples are presented in Table I (below). Gold was also found to be present in the 50 kyrs b2k sample at a concentration of about 19 parts per million. Correspondingly, gold was found at 2 ppm in clear nonmagnetic particles taken from the Gainey Clovis site, hence at a level 10³ times higher than normal crustal abundance.
     Although the Sn, Sb, Au, and Ag in the polar ice samples were at ratios far higher than are observed in carbonaceous chondrites, I concluded at the time that they were nonetheless extraterrestrial and most likely of cometary origin. Whereas carbonaceous chondrite meteorites lose much of their volatile elements during entry through the atmosphere due to frictional heating, such would not have happened to particles dispersed in space as a result of comets being vaporized by superwave cosmic rays. Micron sized particles such as these would have been able to enter the Earth's atmosphere at a relatively low velocity and reach the Earth's surface unheated in their natural state. Hence they would be expected to retain their volatile element components. The recent discovery by Darrah, et al. that certain ferromagnetic particles present at the YD boundary contain tin along with other ET indicators should be considered in light of this prior ice core data. For it is apparent that the tin-bearing dust particles they found came from the same compositionally anomalous source that produced the earlier cosmic dust incursions recorded in polar ice.

(click to enlarge) Figure 5. The author standing next to the Portland State University gamma ray detector used in his neutron activation analysis study of ice age polar dust.

(click to enlarge) Figure 6. The author processing his irradiated samples inside a glove bag prior to counting.

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Table I
Ice Age Cosmic Dust Events

North America             Age (kyrs b2k) Tin Concentration Iridium Concen. Researcher      12,950  25% to 28%   Darrah, et. al. (2007) Greenland           Ice Depth (meters)  Age (kyrs b2k) Tin Concentration Iridium Concen. Researcher   1166 17,000  45% 1 of 8 particles   Thompson (1976) 1212 38,650  710 ppm 16.6 ppb LaViolette (1983a) 1221 45,000   24 ppb   LaViolette (1983a) 1227.7 49,500   24 ppm 6.9 ppb LaViolette (1983a) 1230.5 50,500  2-30% 6 of 7 particles   Thompson (1976)    " 50,500  60 ± 15%* 56 ppb   LaViolette (1983a) 1241 58,700   96 ppb   LaViolette (1983a) 1275 78,500  690 ppm  6.3 ppb LaViolette (1983a) 1342 125,000  3 of 5 particles   Thompson (1976) Antarctica           1585 31,500 < 58 ppm 156 ppb   LaViolette (1983a)

Note: Ice core depths and ages listed above are updated from values given in the 1983 and 1985 publications. Core depths given here record real depth rather than log book depth and ages are older than previously published ages due to improvements in ice core chronology.