[meteorite-list] "Ancient Atomic Bombs" (Libyan Desert Glass)

From: oxytropidoceras at cox.net <oxytropidoceras_at_meteoritecentral.com>
Date: Wed, 4 Nov 2009 23:18:20 -0500
Message-ID: <20091104231820.K4KTW.609608.imail_at_eastrmwml45>

In "Ancient Atomic Bombs" at,
http://six.pairlist.net/pipermail/meteorite-list/2009-October/057786.html
Michael Groetz asked:

"Sand dunes in the Egyptian desert. What
phenomenon could be capable of raising
the temperature of desert sand to at least
3,300 degrees Fahrenheit, casting it into
great sheets of solid yellow-green glass?

The article in question is "Ancient Atomic Bombs" by
Leonardo Vintini, Epoch Times, Oct. 31, 2009,

http://www.theepochtimes.com/n2/content/view/24575/

Contrary to the claims made in the article, an
extraterrestrial impact of some sort is capable of
explaining the Libyan Desert Glass as this material
is commonly called. Many of the objections are made in
this article are based upon a mixture of misinformation
and falsehoods presented in this article; research
either ignored or overlooked by in this article; and
over lack of understanding of what is currently known
about Libyan Desert Glass.

First, the article dismisses the involvement of an
extraterrestrial impact because of the "absence of
accompanying craters in the desert." The absence of an
impact crater in the vicinity of the Libyan Desert
Glass is not problem because an aerial burst, which
would have not left a crater, could have melted the
ground's surface to create it. Various researchers
have used computer models to demonstrate that this
physically possible. they include:

Boslough, M. B. E., and D.A. Crawford, 2008, Low-
altitude airbursts and the impact threat. International
Journal of Impact Engineering. vol. 35, no. 12,
pp. 1441-1448.

Svetsov V. V. and Wasson J. T. 2007. Melting of Soil
Rich in Quartz by Radiation from Aerial Bursts - A
Possible Cause of Formation of Libyan Desert Glass
and Layered Tektites. Abstracts of the Lunar and
Planetary Science Conference. 38th, Abstract no. 1499.

Wasson J. T., 2003., Large Aerial Bursts: An Important
Class of Terrestrial Accretionary Events. Astrobiology.
vol. 3, no. 1, pp. 163-179.

In addition, the Libyan Desert Glass (LDG) occurs as
surface lag composed of loose cobbles, pebbles, and
granules. Since the LDG is found in place, it allows for
a number of explanations of how the material was
created. These include the LDG is what remains of
former melt pool of a crater that has since been
eroded away, leaving a lag of fragmented glass, is
what remains of a solid sheet of glass created by an
aerial burst that has been completely fragmented by
subsequent erosion; and is what remains of impactites
created elsewhere outside its current distribution
and subsequently eroded from its original source, and
transported to where it is now found. There are a
number of pros and cons to these and other ideas
about how LDG formed, which are too lengthy to discuss
in any detail in this post.

The LDG is similar to Mong Nong-type tektites, which
with other Australasian tektites are of impact origin
and lack a known impact crater. ("impact origin" includes
both the terrestrial impact origin and impact of lunar
material hypotheses.) Thus, the LDG is not the only
glassy impactite that lacks a known crater.

Pertinent reference:

Ramirez-Cardona, M., El-Barkooky, A. Hamdan, M. Flores-
Castro, K., Jimenez-Martinez, N. I., and Mendoza-
Espinosa, M., 2008, On the Libyan Desert Silica Glass
(LDSG) transport model from a hypothetical impact
structure. PIS-01 General contributions to impact
structures, International Geological Congress Oslo
2008, Oslo, Norway.

http://www.cprm.gov.br/33IGC/1350834.html

The Epoch time article notes that:

"Neither satellite imagery nor sonar
has been able to find any holes."

The problem here is that "sonar" is not used to find
impact craters on land. In fact, it would be impossible
to use sonar for any purpose in the Sahara Desert where
LDG is found. This misinformation is an excellent
indication of an extreme lack of understanding of basic
science, bordering on illiteracy, on the part of this
article. The stilted and very imprecise use of terminology
in this article also a basic lack of scientific understanding
on the part of this article.

For some information on Sonar go read "Sonar" at:

http://en.wikipedia.org/wiki/Sonar

"...the glass rocks found in the Libyan
Desert present a grade of transparency
and purity (99 percent) that is not typical
in the fusions of fallen meteorites, in
which iron and other materials are mixed in
with the cast silicon after the impact."

1. LDG varies greatly in transparency from being almost
transparent to being either translucent or opaque. There
is nothing about its transparency that preclude LDG from
being an impactite.

2. The percentage of silica in LDG matches the percentage
of silica found in sandstone bedrock that underlies the
areas in which LDG has been found, the location of at least
two impact structures near the area containing LDG; and
larges areas of the desert surrounding both the impact
structures and where LDG is found.

3. The LDG does contain extraterrestrial material derived
from meteorites / an asteroid mixed in with it. This Epoch
Times article is completely wrong about the absence of an
extraterrestrial component being presence within LDG.

A few of very many pertinent papers:

Abate, B., Koeberl, C., Kruger, F. J., and Underwood, J.
R., 1999, BP and Oasis impact structures, Libya, and their
relation to Libyan Desert Glass. In Dressler, B. O., and
Sharpton, V. L., eds., Gpp. 177-192. Geological Society
of America Special Paper no. 339.

Barrat J. A., Jahn B. M., Amosse J., Rocchia R., Keller,
F., Poupeau G. R., and Diemer E., 1997, Geochemistry and
origin of Libyan Desert glasses. Geochimica et Cosmochimica
Acta. vol. 61, no. 9, pp. 1953-1959.

Fudali, R. F., 1981, The major element chemistry of
Libyan desert glass and the mineralogy of its precursor.
Meteoritics. vol 16, pp. 247-259.

Kleinmann, B., 1969, The breakdown of zircon observed
in the Libyan desert glass as evidence of its impact
origin. Earth and Planetary Science Letters, vol. 5,
pp. 497-501.

Koeberl, C., 1996, Libyan Desert Glass: geochemical
composition and origin. In: de Michele, V., ed.,
pp. 121-131, Special publication of the Sahara Journal
- Silica '96. Proceedings of the Meeting on Libyan
Desert Glass and Related Events, July 1996, Milano.

Koeberl C., 2000, Confirmation of a meteoric component
in Libyan Desert Glass from osmium isotopic data.
Meteoritics & Planetary Science. vol. 35 (Supplement),
pp. A89-A90.

Koeberl C., Rampino M. R., Jalufka D. A. and Winiarski
D. H., 2003, A 2003 Expedition into the Libyan Desert
Glass Strewn Field, Great Sand Sea, Western Egypt.
Proceedings of the meeting on Large Meteorite Impacts
(2003), Lunar and Planetary Institute, USRA, Center of
Advanced Studies, Abstract no. 4079.

This epoch times article also stated:

"However, this doesn't explain how two of
the areas found in close proximity in the
Libyan Desert show the same pattern the
probability of two meteorite impacts so
close is very low."

Part of the problem here, is that the people who promote
the Libyan desert glass (LDG) as evidence of ancient
nuclear warfare ignore the fact that the LDG occurs as
erosional lags produced by the erosion, transportation
and redeposition of pieces of it over a period of millions
of years. Contrary to poetic descriptions by various
alternative archaeologists and early geologists, the "
glass fields" are not primary deposits formed by the either
the original airfall, base surge, or in place melting of
local sand. Rather, the LDG occurs as secondary, even
tertiary, concentrations, created over 26 million years,
of the more resistant pieces of LDG. The original Neogene
deposits, which either contained the LDG or on which formed
or fell have been eroded and the LDG released from them,
possibly transported some distance; and concentrated as
an erosional lag on the ground surface. As a result, the
current distribution of LDG likely is unrelated to its
origin. The present distribution of LDG reflects what has
happened to it over the last 26 million years instead of
how it was created.

Finally, the Epoch Times article states:

"Nor does it explain the absence of water
in the tektite specimens when these areas of
impact were thought to be covered in it some
14,000 years ago.'

1. The intense heat of formation of LDG is perfectly capable
of explaining its extremely low water content.

2. The LDG formed about 29 million years ago, not 14,000
year ago as this article incorrectly states above. Given
the age of LDG, it is impossible for this material to have
any connection with modern humans and manmade objects such
as nuclear weapons.

A few of many pertinent references:

Horn P., M?ller-Sohnius D., Schaaf P., Kleinmann B. and
Storzer D., 1997, Potassium-argon and fission-track dating
of Libyan Desert Glass and strontium and neodymium constraints
on its source rocks. In: de Michele, V., ed., pp. 59-73,
Special publication of the Sahara Journal - Silica '96.
Proceedings of the Meeting on Libyan Desert Glass and Related
Events, July 1996, Milano.

Matsubara, K., Matsuda, J.I., and Koeberl, C., 1991, Noble
gases and K-Ar ages in Aouelloul, Zhamanshin, and Libyan
Desert impact glasses. Geochimica et Cosmochimica Acta
vol. 55, pp. 2951-2955.

This article fails to provide any convincing evidence that
there is any connection between LDG and ancient nuclear
warefare and that LDG is not an impactite. This Epoch Times
article does provide a lot misinformation and simply ignores
any research that contradicts its preconceived notions about
how LDG might have formed.

Yours,

Paul H
Received on Wed 04 Nov 2009 11:18:20 PM PST