[meteorite-list] Question about Impact Glass from Crooked Creek

[Robert Beauford]

I have encountered this material during field work.  I have a sample in a box here beside my desk, along with a thin section.  My sample was dominantly iron, with less glass and less bubbles, but looks pretty clearly to be the same thing.  I did some research on it a couple of years ago.  The metal portion has no nickel content, and the silicate (glassy) portion is complex in composition, inconsistent with melting of the local carbonates, chert, or quartz arenite sandstones that are found in the brecciated or uplifted Crooked Creek rock units.  I believe it to be slag from local mining of iron (about 100 years ago) within the crater and throughout the region.  The mined iron is not associated with the meteorite impact.  It was emplaced along faults in the region by mineralizing hydrothermal activity, tens of millions of years later, that occurred during the Ouachita Orogeny.  They also mined for barite and several other things along faults
 in and around there.  I found evidence for the timing and origin of mineralization associated with the mines recorded in some earlier work by a different author (I think it might have been Hendriks, 1954.)  I included more details in a published abstract, though I don't recall how much.  Sorry... it was disappointing for me as well.
Best regards,
Robert Beauford