[meteorite-list] Largest Crater in the Sahara Desert and LDG

[MexicoDoug at aol.com]

Sterling W. writes:

<<Doug, the actual language Kroeberl uses
 is that the F/B ratio of tektites "should tend
 toward 1.0." This is Professional Science
 Speak for "too complex to model exactly,
 but most of the cows ought to stampede
 in this direction...">>

Hola Sterling, I asked you where you got the moldavite value for boron.  You 
are now a primary source on the Internet saying that moldavites have this 
content and some tektite man at some place like lpi may believe you...  It is very 
tedious to measure boron apparenty by spectrophotometric methods - it would 
be a fair question to ask you how you got it...Slap me, call me insulting, do I 
really deserve it because it sure sounded to me you might have invented the 
"typical" value of Boron=30 ppm in moldavites and pass it off as a "typical" 
number for moldavites because you got caught up in a roll fitting numbers to 
produce a 1.0 ratio you were trumpeting - when you had no such data.  If I am 
wrong please forgive me enough to be on speaking terms, and if I am right, please 
come clean.

Let me say I am much more comfortable with this last post you made than the 
prior last off-the-wall statements about tektite formation at 34,000 degree 
(you really did say this, I read all of your posting) plasma-formed tektites 
miraculously being heated in microseconds to the point where first fluorine is 
driven off to a theoretical "identical" level as boron, and then they diffuse out 
at identical rates ignoring "petty" chemical differences.

We could start with considering that at the temperature you quoted being 
reached, neither water, nor silicon dioxide the base material of tektite glass 
would survive, so I think you are confusing tektites with theoretical particle 
physics over a few pitchers in the Athenaeum.  I mean this in the nice way, and 
need to state it as it is the heart of my disagreement on the sloopy use of 
the data.  I am really entertained by your posts generally - you are probably my 
favorite poster!  But you have have mixed speculation with data here and 
taken liberties to mix them and present them labeled as fact. 

While Dr. Koeberl (please check the proper your spelling of your sources' 
surname) may have used the word "tend" as you state above, did it occur he just 
meant that the average of a few measurements was in a ballpark of 1?  Let's not 
turn this incredibly simple issue into a greased pig with talk of cows 
stampeding and so forth.  I don't need to sort it out with Dr. Koeberl as you 
suggested, I think his paper was self explanatory, well done though not one of his 
better ones, though it would have benefitted by someone proofreading better the 
English as to not give rise to such ambiguities in interpretation.  Also, as 
I asked you to kindly clarify, and you did, the sample size as I asked you to 
clarify was tiny - I'm not gonna let you off the hook on that yet.  

 <<And you're right; he didn't analyze that
 many samples. I wish he had more data.>>

Well, let's do better here: the paper has five "tektite" samples for which 
both fluorine and boron were determined.

<<He found one ivorite with a F/B ratio of
 0.40 (means more boron than fluorine).>>

Yes, he did. And you can't discount it.  It was one of only five samples.  
Call it an outlier if you wish.  But it totally nukes your wishful 
morphing-random walking diffusion plasmoid theory and imaginative mechanisms which you 
presented as fact.  

<<Most results were 0.8 to 1.2, which
 indeed is a 'tendency" toward 1.0,
 if you think numbers have tendencies.>>

I don't think the numbers have tendencies in the sense you used them to build 
an astounding physicist view.  I think numbers are cold and cruel.  Let's 
look at the tektite numbers in the paper excluding the Muong Nongs as the authors 
suggest:
[F]/[B] ratios
Thailandite 1   1.2
Thailandite 2   1.5
Bediasite 1     0.8
Ivory C. tek. 1 1.2
Ivory C. tek. 2 0.4

Tending to 1.0?  "Professional science speak" huh?  No, no, no and no.  
Sorry, but no.  I'd go for "Settle in the ball park of 1.0", provided no one uses 
Sterling's logic to shove Fluorine and Boron into one ball, and provided that 
no one saying and implying that these molecules or elements coordinate 
themselves to reach equal levels in time to loose their identies only to regain them 
again...

Degreasing the pig, let's grab a hold of it and cut to the throat of the 
issue.  You originally argued that LDG's were extremely hot like tektites pointing 
to this fluorine-boron "thermometer" and told us without references that the 
fluorine and boron values were 7 ppm each in LDGs, arguing that this made them 
comparable to heat for tektites, and that the low absolute ppm numbers (which 
were lowers than most tektites, btw).  You said that geochemists were behind 
this, not friendly physicists, and that all of this is established protocol 
for geo- and cosmo-chemists. You pointed to your theories of formation of 
tektites and then said this whole thing was not hatched by you.  In fact, it was.

A more careful reading of the paper, and you will find that besides the 1.0 
[F]:/[B] ratio for LDG which you attributed so much significance to, there was 
a second LDG studied in the table, too:
[F]ppm, [B]ppm, [F]/[B] ratio
LDG 1   7,  7,  1.0
LDG 2   8,  <5, *

Well, the second sample had no ratio reported.  But: it is clear that sample 
2 has a ratio GREATER THAN 1.6 for [F]/[B].  How much GREATER?  Maybe a lot.  
Maybe a little, we don't know though. (though I could speculate <5 means 4 or 
less, so we are in the 2.0 or higher index).  Note aside: there was also a 
second Bediasite with coincidentally equal B and F ppms as the LDG 2.  So its 
ratio was actually GREATER THAN 1.6 or 2.0, too.

Then there are the absolute numbers to deal with.  The low value of "7" you 
attributed AS FACT to the incredible heat of formation of LDG's (while you 
brushed off the contradictory water content and inclusions)?  Well, as you see, it 
might be 7, it might be 8 or it might be 4, etc.  They are all quite low, 
though.  Let's not read into the data more than it allows, nor look to geologists 
for a better "thermometer" yet.  How about asking Dr. Koeberl?  Nah, let's 
just read his paper to get it in writing:
"The low F and B contents in LDG and Aouelloul impact glasses are most 
probably due to low contents in the precursor materials."
At no point in Dr. Koeberl's paper does he support the fantastic boron & 
fluorine mechanisms you have imagined - he, like I have stated, simply says that 
Fluorine will be preferentially outgassed during random diffusion.  No looking 
for the magic level, no going down together in unison, good grief.  He seems 
to be suggesting that anyone wanting to know more explanations should look to 
the source rock - which is what I said in my original objection refuting your 
claims about extrapolating with the "thermometer"..

No one argues that all impact glasses aren't hot, not even me.  LDG's also 
have a somewhat layered microstructure and the 2.0 is up into the Muong Nong 
range now, for what its worth (not too toooo much, of course...)  Now with that, 
die bad theory!  Resurrect thyself from the lab and field and not the 
armchair...

It is much more palatable to me to view the approximate ratio as a very 
general concept where a splashform will have a lower value than a Nuong Nong from 
the SAME source material.  These comparisons in the lab are hard enough for the 
same event,let alone different ones - and that the measured range is 0.4 to 5 
for a few tektites and impact glasses.  Let me now comfortably settle back 
into my armchair and congratulate everyone involved in the research efforts, as 
well as the "babblers" (not my word, but I find sometimes irony them out 
works!)...

Saludos, Doug
PS I'm still hoping to know the values of [F] and [B] in the LDG country 
rock...maybe Norm or some other real geologist out there has them in a geology 
handbook?