[meteorite-list] Aswan Rock - Opinions?

From: N Lehrman <nlehrman_at_meteoritecentral.com>
Date: Thu Apr 22 10:17:45 2004
Message-ID: <00bf01c3c0c8$a6477940$dea4fea9_at_homeportal.2wire.net>

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Jeff & list,

I've spent my career with rocks like that! It is a hydrothermal breccia =
from a low-sulfidation epithermal vein system. You'll notice that some =
of the clasts have quartz/chalcedony hairlines healing jigsaw-puzzle =
breccias (pieces would still fit neatly back together, not jumbled or =
significantly displaced). This is hydraulic fracturing that forms as =
fluid pressures exceed lithostatic pressures, just before a hydrothermal =
explosion. Once the system cracks and explodes, fluid streaming does =
jumble and rotate most of the clasts. Your rock likely contains =
anomalous amounts of As, Hg, Sb, and quite possibly, Au and Ag. The =
rounded exterior is simply from erosion and water transport. From the =
photos I can't tell for sure what the clasts are, but I would guess they =
are rhyolite (a common associate of this style of mineralization). =20

Merry Winter Solstice and a Happy New Orbit to All,

Norm Lehrman
(http://TektiteSource.com)=20


  ----- Original Message -----=20
  From: Jeff Kuyken=20
  To: Meteorite List=20
  Sent: Friday, December 12, 2003 2:38 AM
  Subject: [meteorite-list] Aswan Rock - Opinions?


  Hey all,

  When I was in Egypt in October, I jumped onto a young half-trained =
CCRRAAZZYY camel and headed out into the desert. Among a few rocks =
(mostly fossils) I found an interesting stone which was nothing like the =
others in the area. I don't think it is a meteorite but it does look =
like some kind of breccia. It is a broken quarter sphere in shape and =
the photos are of the two broken surfaces. I'd appreciate any opinions =
on this one. The links are:

  http://www.meteoritesaustralia.com/images/Aswan 1.jpg

  http://www.meteoritesaustralia.com/images/Aswan 2.jpg

  Cheers,

  Jeff Kuyken
  I.M.C.A. #3085
  www.meteorites.com.au
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<DIV><FONT size=3D2>Jeff &amp; list,</FONT></DIV>
<DIV><FONT size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT size=3D2>
<DIV><FONT size=3D2>I've spent my career with rocks like that!&nbsp; It =
is a=20
hydrothermal breccia from a low-sulfidation epithermal vein =
system.&nbsp; You'll=20
notice that some of the clasts have quartz/chalcedony hairlines healing=20
jigsaw-puzzle breccias (pieces would still fit neatly back together, not =
jumbled=20
or significantly displaced).&nbsp; This is hydraulic fracturing that =
forms as=20
fluid pressures exceed lithostatic pressures, just before a hydrothermal =

explosion.&nbsp; Once the system cracks and explodes, fluid streaming =
does=20
jumble and rotate most of the clasts.&nbsp; Your rock likely contains =
anomalous=20
amounts of As, Hg, Sb, and quite possibly, Au and Ag.&nbsp;The rounded =
exterior=20
is simply from erosion and water transport.&nbsp; From the photos I =
can't tell=20
for sure what the clasts are, but I would guess they are rhyolite (a =
common=20
associate of this style of mineralization).&nbsp; </FONT></DIV>
<DIV>&nbsp;</DIV>
<DIV>Merry Winter Solstice and a Happy New Orbit to All,</DIV>
<DIV>&nbsp;</DIV>
<DIV>Norm Lehrman</DIV>
<DIV>(<A href=3D"http://TektiteSource.com">http://TektiteSource.com</A>) =
</DIV>
<DIV>&nbsp;</DIV>
<DIV>&nbsp;</DIV></FONT></DIV>
<BLOCKQUOTE dir=3Dltr=20
style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; =
BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
  <DIV style=3D"FONT: 10pt arial">----- Original Message ----- </DIV>
  <DIV=20
  style=3D"BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: =
black"><B>From:</B>=20
  <A title=3Djeff_at_meteoritesaustralia.com=20
  href=3D"mailto:jeff_at_meteoritesaustralia.com">Jeff Kuyken</A> </DIV>
  <DIV style=3D"FONT: 10pt arial"><B>To:</B> <A=20
  title=3Dmeteorite-list_at_meteoritecentral.com=20
  href=3D"mailto:meteorite-list_at_meteoritecentral.com">Meteorite List</A> =
</DIV>
  <DIV style=3D"FONT: 10pt arial"><B>Sent:</B> Friday, December 12, 2003 =
2:38=20
  AM</DIV>
  <DIV style=3D"FONT: 10pt arial"><B>Subject:</B> [meteorite-list] Aswan =
Rock -=20
  Opinions?</DIV>
  <DIV><BR></DIV>
  <DIV><FONT size=3D2>Hey all,</FONT></DIV>
  <DIV><FONT size=3D2></FONT>&nbsp;</DIV>
  <DIV><FONT size=3D2>When I was in Egypt in October, I jumped onto a =
young=20
  half-trained CCRRAAZZYY camel and headed out into the desert. Among a =
few=20
  rocks (mostly fossils) I found an interesting stone which was nothing =
like the=20
  others in the area. I don't think it is a meteorite but it does look =
like some=20
  kind of breccia. It is a broken quarter sphere in shape and the photos =
are=20
  of&nbsp;the two broken surfaces. I'd appreciate any opinions on this =
one.=20
  The&nbsp;links are:</FONT></DIV>
  <DIV><FONT size=3D2></FONT>&nbsp;</DIV>
  <DIV><FONT size=3D2><A=20
  href=3D"http://www.meteoritesaustralia.com/images/Aswan =
1.jpg">http://www.meteoritesaustralia.com/images/Aswan=20
  1.jpg</A></FONT></DIV>
  <DIV><FONT size=3D2></FONT>&nbsp;</DIV>
  <DIV><FONT size=3D2><A=20
  href=3D"http://www.meteoritesaustralia.com/images/Aswan =
2.jpg">http://www.meteoritesaustralia.com/images/Aswan=20
  2.jpg</A></FONT></DIV>
  <DIV><FONT size=3D2></FONT>&nbsp;</DIV>
  <DIV><FONT size=3D2>Cheers,</FONT></DIV>
  <DIV><FONT size=3D2></FONT>&nbsp;</DIV>
  <DIV><FONT size=3D2>Jeff Kuyken<BR>I.M.C.A. #3085<BR><A=20
  =
href=3D"http://www.meteorites.com.au">www.meteorites.com.au</A></FONT></D=
IV></BLOCKQUOTE></BODY></HTML>

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Received on Fri 12 Dec 2003 10:57:28 AM PST


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