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Re: Leaned something new! RE: Some Data ....



Because not all fossils are bone hard, dry, or 'rockicized', even if they date 
back that far. A good deal of Hell Creek material is preserved in matrix 
containing a lot of clay, which swells when wet and shrinks when dry. As clay 
seeps into fractures, pores, joints, etc. this leads to increased fracturing of 
those bones, especially when weathering brings them closer to the surface. This 
results in a lot of Hell Creek fossils that look nice on the surface, but the 
cancellous or spongey part of the bone underneath that is literally a 
mineralogical house of cards. Applying consolidant SLOWLY helps to fill in 
microscopic fractures, fill pore spaces, and shore up the inner structure of 
the fossil. It's not easy to do in the field, especially if you're working with 
damp matrix. It's time consuming, but totally worth it when the specimens get 
to the laboratory prep. stage. Hosing the specimen down quickly with the same 
consolidant can wash it away like a
 sandcastle at high tide.

The term 'preservative' reminds me of the ones used in food. Consolidants don't 
prevent chemical breakdown of fossil material, and can even speed it in some 
instances if it sets off chemical reactions. They provide structural support 
more than anything else.

Michelle Pinsdorf
South Dakota School of Mines and Technology

--- On Sun, 11/1/09, Dora Smith <villandra@austin.rr.com> wrote:

> From: Dora Smith <villandra@austin.rr.com>
> Subject: Re: Leaned something new!  RE: Some Data ....
> To: wdm1949@hotmail.com, "DML" <dinosaur@usc.edu>
> Date: Sunday, November 1, 2009, 10:15 AM
> Someone fill in this amateur.
> 
> You've got a 70 million plus year old bone hard, dry,
> rockicized fossil.
> 
> Why on earth would you add a preservative?
> 
> Yours,
> Dora Smith
> Austin, TX
> tiggernut24@yahoo.com
> 
> ----- Original Message ----- From: "dale mcinnes" <wdm1949@hotmail.com>
> To: "DML" <dinosaur@usc.edu>
> Sent: Sunday, November 01, 2009 10:37 AM
> Subject: FW: Leaned something new! RE: Some Data ....
> 
> 
> > 
> > <1257024771.4aecad03dc4f1@webmail.chariot.com.au>
> > Content-Type: text/plain; charset="iso-8859-1"
> > Content-Transfer-Encoding: quoted-printable
> > MIME-Version: 1.0
> > 
> > 
> > As a side note here=2C even perfectly formed undamaged
> fossils
> > can on occasion turn instantly soggy by simply adding
> a preservative
> > whilest in the field. You can instantly turn fossils
> into mush by
> > doing so. It would appear that if they are laced with
> 1000s of tiny microsc=
> > opic fractures and you add a liquid=2C they will flow.
> One has=20
> > to add preservatives one drop at a time=2C allowing
> each drop to harden
> > before applying the next application. I believe this
> is the reason most
> > fossils are destroyed when amateurs attempt to recover
> them.  --dale=20
> > 
> > ----------------------------------------
> >> Date: Sun=2C 1 Nov 2009 08:32:51 +1100
> >> From: dannj@alphalink.com.au
> >> To: dinosaur@usc.edu
> >> Subject: Re: Leaned something new! RE: Some Data
> ....
> >> 
> >> On Sat=2C Oct 31st=2C 2009 at 4:58 AM=2C B tH=20
> >> wrote:
> >> 
> >>> I never have heard that fossils could be in
> such
> >>> a condition. I have seen some rocks that were
> easily
> >>> crunched up by hand - must be along the same
> lines.
> >>> When things like this occur=2C is it due to
> something that
> >>> has happened to the fossil "recently" - how
> could it
> >>> have survived up till now in such a state?
> >> 
> >> I suspect most 'oatmeal' fossils are due to
> chemical changes that have
> >> occured while they were in the upper soil layers.
> They were probably
> >> much harder for most of their fossil 'life'=2C
> otherwise you'd think that
> >> pressure put on them at any decent depth would
> squish them beyond
> >> recognision. Keep in mind that even solid and
> apparently hard bone can
> >> gradually 'flow' under immense pressures=2C
> resulting in distortion of th=
> > e
> >> fossil.
> >> 
> >> --
> >>
> _____________________________________________________________
> >> 
> >> Dann Pigdon
> >> GIS / Archaeologist Australian Dinosaurs
> >> Melbourne=2C Australia http://home.alphalink.com.au/~dannj
> >>
> _____________________________________________________________
> >>    =20
> >
> _________________________________________________________________
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>