[meteorite-list] Fusion Crust
From: MstrEman <mstreman_at_meteoritecentral.com>
Date: Fri, 12 Oct 2012 19:26:34 -0400 Message-ID: <CAPwdm9GJH1wDh5dr93c+CoMDbWAEw0B=3T39JSbZF+xtQyXy4A_at_mail.gmail.com> In the totally "for what its worth" category... As to what the crust might be like chemically , I'll have to think it through more but what comes to mind first is instead of much magnetite ( Iron Oxide: Fe3O4)) which gives OCs that velvet look, one might find the variations on the nickel iron carbides and carbonates. Probably very little carbonate because it tends to decompose at earthly reentry temperature. Magnetite it seems is formed but gets recycled. Iron Carbide has a graphite-like metallic color. "The thermal decomposition of carbon dioxide has been investigated behind reflected shock waves at temperatures of 3200?4600K and pressures of 45?100kPa " BUT "The CO2 decomposition occurs in two steps at temperatures near 773 K: First wustite (FeO) reacts with CO2 to form carbon monxide (CO) and magnetite (Fe3O4); then CO disproportionates to C(gr) and CO2. Fe3O4 can be recycled to Fe1-yO by thermal dissociation above 2200 K... " Iron minerals: iron carbide (cementite) or iron carbonate (siderite) nickel minerals nickle carbide (cohenite) and nickle carbonate (zaratite) The Nickel-Iron intermediary minerals ferro-nickel carbide(Haxonite ) ferro-nickel magnesium carbonate ( Gaspeite). All of the carbides have been found in meteorites already. The carbonates probably many have been after terrestrial alteration on earth. Like was said would be really insightful if we were able to take stock of a meteorite's crust on the surface of Mars. Elton Received on Fri 12 Oct 2012 07:26:34 PM PDT |
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