Beryllium-10 Study on the Origin of Tektites

Paul bristolia at yahoo.com
Thu May 29 12:52:31 EDT 2008

While looking for something else I came across an
interesting tektite study. It is;

Serefiddin, F., G. F. Herzog, and C. Koeberl, 2007,
Beryllium-10 concentrations of tektites from the
Ivory Coast and from Central Europe: Evidence for
near-surface residence of precursor materials.
Geochimica et Cosmochimica Acta. vol. 71, no. 6,
pp. 1574-1582 (March 15, 2007) doi:10.1016/j.gca.2006.12.007

To get the abstract of this article enter the above
doi number in the box at http://dx.doi.org

they concluded:

"Although not definitive, consideration of several possible
cosmic-ray exposure histories suggests that about half the
interior 10Be has a meteoric origin, which if corrected to the
time of formation yields a concentration compatible with
those measured in typical contemporary soils. The observations
are consistent with the formation of three of the four main
tektite groups from surface soils or sediments."

Yours,

Paul H.

New Paper on Lunar meteorite, Miller Range (MIL) 05035

Paul bristolia at yahoo.com
Thu May 29 10:37:22 EDT 2008

A paper about a new lunar meteorite has been accepted for
publication in Geochimica et Cosmochimica Acta. It is:

Joy, K. H., I. A. Crawford, M. Anand, R. C. Greenwood, I. A.
Franchi, and S. S. Russell, in press, The Petrology and
Geochemistry of Miller Range 05035: A New Lunar Gabbroic
Meteorite. Geochimica et Cosmochimica Acta.

Miller Range (MIL) 05035 is identified as a lunar gabbroic
meteorite. Its mineralogy, bulk-rock chemical composition and
the bulk oxygen isotope values are similar to those of other
mare basalts. It consists predominately of pyroxene grains
with large plagioclase feldspars and accessory quartz, ilmenite,
spinel, apatite and troilite. This meteorite is similar to
Asuka-881757 and Yamato-793169 and basaltic regolith
breccia MET 01210.

Yours,

Paul H.

penny just dropped - Reflected Light Petrography

Paul bristolia at yahoo.com
Sat May 17 20:32:21 EDT 2008

Dave Harris wrote:


>I am sure I saw some reference on the list about

>these Nantan thin sections that appear on Fleabay.

>Having just got a polarizing scope I just realised

>that they can either be ruut t/s or completely

>opaque as Fe and sulphides are opaque to the

>standard 30 micron thickness, and would be a

>bit dull anyway - expecially looking at rust!

>How funny - shows I learnt SOMETHING already

>about mineral optics


There are petrographic microscopes, which use reflected polarized light to
conduct petrographic analysis of opaque minerals in polished thin sections.
To take advantage of reflected light petrography, the thin sections usually
have to be polished.

Determination of opaque minerals in reflected light microscopy
http://www.unige.ch/sciences/terre/mineral/fontbote/opaques/opaques_properties.html

Ore Petrology and Phase Equilibria
http://www.agu.org/revgeophys/mckibb01/node11.html

Ore (Petrographic) Microscopes
http://www.oremicroscopes.com/

Trinocular Ore Polarizing Petrographic Microscope
http://usbmicroscopes.biz/usb-microscope/trinocular-ore-polarizing-petrographic-microscope/

A couple of books:

Ore Microscopy and Ore Petrography by James R. Craig and David J.
Vaughan (1994), ISBN:0471551759

Atlas of the Textural Patterns of Ore Minerals and Metallogenic
Processes by S. S. Augustithis (1995) ISBN:3110136392

Bunch, T. E. and A. M. Reid, 1975, The Nakhlites. I - Petrography and mineral
chemistry. Meteoritics. vol. 10, pp. 303-315, pp. 317-324.

Yours,

Paul H.

A New Question (Antarctic Politics)

Paul bristolia at yahoo.com
Thu May 15 23:43:14 EDT 2008

Martin Altmann pondered:

“Besides... I have some ideas (sorry, happens from time
to time):

Could it be also a reason for Antarctic meteorites never
can't be traded, that according the Antarctic treaties,
none of the governments involved in Antarctic hunts
can't get ownership in these meteorites?”

For a discussion of the politics of doing science in Antarctic, there
is a delightful article. It is:

Naylor, S., M. Siegert, K. Dean and s. Turchetti, 2008, Science,
geopolitics and the governance of Antarctica. Nature Geoscience.
vol. 1, no. 3, pp. 143 – 145. doi:10.1038/ngeo138

http://www.nature.com/ngeo/journal/v1/n3/index.html#fe

Yours,

Paul H.

Terrestrial Meteorite Hunting on the Moon

Paul bristolia at yahoo.com
Tue May 6 09:31:42 EDT 2008

Dear Friends,

In the most recent issue of Astrobiology, there is an article advocating
the collecting of terrestrial meteorites from the Moon. They suggest that
there are pieces of the ancient Earth, blasted into space from the
surface of early Earth to be found on the Moon as "terrestrial
meteorites". They argue that an unique record of early Earth might
be found on the Moon in the form of "terrestrial meteorites".

The paper is;

Ian A. Crawford, Emily C. Baldwin, Emma A. Taylor, Jeremy A.
Bailey, Kostas Tsembelis, 2008, On the Survivability and Detectability
of Terrestrial Meteorites on the Moon. Astrobiology. vol. 8, no. 2,
pp. 242-252. doi:10.1089/ast.2007.0215.

http://www.liebertonline.com/doi/abs/10.1089/ast.2007.0215

Best Regards,

Paul H.