[meteorite-list] Seeking Impact Materials

[Robert Beauford]

Ted,
Yes.  It was no small process to collect the samples.  Weeks of research went in to preparing for the trip, and even at that I did not feel confident enough in what I initially collected along the highway to reliably call it KT boundary material, for exactly the reasons you point out,... though I did spend quite a while squatting precariously on a very uncomfortably steep slope over the cut above the access road.  I did finally locate the iconic layer in a good clear exposure outside nearby Cokedale, a location that has been decribed as one of the best in the world.  After collecting, I followed the exposure for a half mile or so down the railroad tracks there... a truly memorable walk.  If I didn't have hundreds of hours of experience tracing subtle difference in dolomite and slight variations in sand or silt content in limestone for miles through the valleys of the Ozarks, I don't know that I would have found it.
As it is, it was one of my more enjoyable outings.  
-Robert Beauford

--- On Wed, 1/19/11, Ted Bunch <tbear1 at cableone.net> wrote:

> From: Ted Bunch <tbear1 at cableone.net>
> Subject: Re: [meteorite-list] Seeking Impact Materials
> To: "Robert Beauford" <robertbeauford at rocketmail.com>, meteorite-list at meteoritecentral.com
> Date: Wednesday, January 19, 2011, 2:20 AM
> You ask a lot - there are good
> impactites offered at the Tucson show and on
> the internet. If you collected in the Raton Pass/ S of
> Trinidad road cuts
> along the Interstate or outlier sites from the Interstate
> in the region, I
> hope you had a knowledgeable field guide with you. Most of
> these exposures
> are slumped over. If you collected elsewhere in the region
> at a "clean"
> site, the "fireball layer" is difficult to resolve even if
> you are a trained
> geologist and even then, it is a ball buster to recognize
> the K/T layer.
> Clay layer look-a likes are intercalated with thinly bedded
> carbonaceous
> shales and coal seams and this sequence is typically meters
> thick on either
> side of the boundary.
> 
> Good luck,
> 
> Ted Bunch
> 
> 
> 
> On 1/18/11 5:42 PM, "Robert Beauford" <robertbeauford at rocketmail.com>
> wrote:
> 
> > Dear friends,
> > I would like to put together an educational collection
> of impact materials.  I
> > need examples of a variety of impactites.  I've
> got tektites and moldavite,
> > but would like partial melts, highly shocked
> materials, breccias, suevites,
> > and so on, with their crater of origin (and preferably
> location in relation to
> > the crater).  I particularly need materials that
> will show microscopic shock
> > alteration features in thin section.  I recently
> collected a quantity of
> > really nice coherent samples of KT boundary material
> from the legendary
> > outcrops near Trinidad, in Southern Colorado, and
> would be happy to send a
> > provenanced piece of this, along with my sincere
> thanks, to anyone that is
> > willing to send me nice, labeled materials that I can
> use.
> > 
> > Please reply off list, and I will supply my personal
> mailing address and get
> > yours (if you are interested in the KT material in
> return).
> > Thank you, in advance, for your assistance.
> > -Robert Beauford
> > 
> > 
> >       
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