[meteorite-list] Clarification.. Was Fusion Crust on Irons

From: MEM <mstreman53_at_meteoritecentral.com>
Date: Thu, 19 Nov 2009 21:08:41 -0800 (PST)
Message-ID: <638229.27884.qm_at_web55208.mail.re4.yahoo.com>

Again Yahoo is near comatose and I am not getting all the posts.

We are going to eventually see a predominately iron meteorite which is going to have a legitimate "fusion crust" (meeting the definition).

When I said "non -silicate" bearing I meant insignificant silicate content and was trying to establish and end point for a series, mineralogically and metaphorically speaking--otherwise... as has happened here time and time again, people start throwing in exceptions and progress stops. (e.g. Campo was non-silicate bearing until someone found a silicated batch).

Discussion is complicated by the lack of adequate definitions/ descriptions. They abound especially in a rare commodity. For another vexing example of undefined: how many atoms of copper, gold or lead need be in a "glob" in a meteorite to legitimately say that a meteorite has native Cu, Au, or PB? Every meteorite has an C,A,P atom so or per billion but where do we draw the line on declaring it?


So you all know where I am going with this: I would like to see a new list of terms used in our field which ensures we are discussing the same thing/feature observed on multiple meteorites. I think many agree that as the term fusion crust is now defined and how it is actually used to refer to every eventual possible appearance-- even on rusty iron shale( yes someone has offered "fusion crusted" iron shale before) and fusion crusted paleo meteorites-- are very different things and that we need a better convention of what is and or is not the result of flight and how it relates to surface features in general on all types of meteorites. Suprisingly, very little science has been focused on the formation and features of "fusion crust" especially compared to the internal content. Even less effort has been directed are promoting operational terms to describe what is observed on different surfaces.

Personal business has taken me far from the list for several weeks so if I haven't addressed your message please feel free to resend. I may not be active on the beloved list but I am getting some lab work done and hope to announce some really neat things next year.

Happy Thanksgiving for those that celebrate the season... Hope to be back before Christmas and BTW what dates are the Las Vegas(ahem)Gem and Mineral Show?

Elton
Received on Fri 20 Nov 2009 12:08:41 AM PST