Re: Kensington Runestone - Nielsen and Wolters.


Lisbeth Andersson wrote:
<snip>
> And when is somebody going to start the obvious experiment?
<snip>
> *What we know is not nearly as interesting as *how we know it.

Lisbeth:
Indeed, it would be interesting to know
*how the various claimants of geological conclusions
re: the KRS know what they know.

Such investigations have been done elsewhere;
these are the sorts of references that we need
before we can begin to assess the applicability of
Wolter's Maine tombstone observations to the KRS.
From the bibliography at the end of:

Roberts, S.M.
2005
Surface-recession weathering of marble tombstones:
New field data and constraints
_In_ Turkington, A.V., ed.
Stone decay in the architectural environment
Geological Society of America Special Paper 390, p. 27-37
doi: 10.1130/2005.SPE39004.

Seen at:

https://uascentral.uas.alaska.edu/onlinelib/Spring-2005/GEOL301-J01/TombstonesSMR.pdf

Livingston, R.A., and Baer, N.S.
1990
Use of tombstones in investigation of deterioration of stone monuments
Environmental Geology and Water Science, v. 16, no. 1, p. 83-90

Cooke, R.U., Inkpen, R.J., and Wiggs, G.F.S.
1995
Using gravestones to assess changing rates of weathering in the United
Kingdom
Earth Sur-face Processes and Landforms, v. 20, p. 531-546

Inkpen, R.J.
1998
Gravestones: Problems and potentials as indicators of historic changes
in weathering
_In_ M.S. Jones and R.D. Wakefield, eds.
Aspects of stone weathering, decay and conservation: Stone Weathering
and
Atmospheric Pollution Network '97: London, Imperial College Press, p.
16-27

Matthias, G.
1967
Weathering rates of Portland Arkose tombstones
Journal of Geological Education, v. 15, p. 140-144

If acid rain artificially weathered Maine tombstones,
increasing the amount of weathering, then maybe
its principal constituents (sulphuric acid and nitric acid)
artificially weathered the KRS.
For the observations of weathering of Maine tombstones to be
comparable to the weathering of the KRS, a comparison of
the effects of acid rain on the KRS must be done, to
eliminate the acid rain variable from the comparison.
Perhaps a piece of the KRS could be knocked off and
given an "acid test", e.g. as from:

http://www.customelec.com/micamylar.asp

"Capacitor grade reconstituted mica paper is manufactured from natural
muscovite mica
(K2 Al4 [Si6 Al2 O20] (OH, F)4).
This mica is subjected to a process in which it is heated to
approximately 870°C.
This heat causes the mica crystal to partially dehydrate and
release a portion of the water which is bonded naturally in the
crystal.
When this occurs, the mica partially exfoliates, resulting in smaller
particles.
The heated mica is then quenched in a mild alkaline solution, cooled,
drained, and
subjected to a weak sulfuric acid solution.
The chemical reaction between the caustic and the acid
generates a gas between the laminae, which
causes the mica to expand greatly.
The mica is then ground to produce small particles.
"

From a page on biotite mica:

http://www.geology.neab.net/minerals/biotite.htm

"Soluble in concentrated sulfuric acid."

Here's one that should be interesting, inasmuch as it details
the differences in weathering response of different types of biotite
with different chemical compositions (biotite is the mica that was
being compared by Wolter, type not specified by him, AFAIK)
to nitric acid:

Biotite dissolution processes and mechanisms in the laboratory and in
nature

http://www.minsocam.org/MSA/AmMin/TOC/Articles_Free/2003/Murakami_p377-386_03.pdf

"
A comparison of our data with results of other studies indicates that
the formation of vermiculite layers between biotite layers occurs even
in the early stage
when biotite is not Fe-rich
[more than 0.8 Mg per O10(OH)2].
When biotite is Fe-rich
[less than 0.4 Mg per O10(OH)2]-like the present one-
released Fe is precipitated as, for example, Fe hydroxide, and
vermiculite is rarely formed because of limited availability of Mg.
Thus,
a higher Mg content in biotite
facilitates the formation of vermiculite, at least in the early stage.
Because vermiculite dissolves at a much slower rate than biotite,
Mg-rich biotite
dissolves at a slower rate than
Fe-rich biotite.
In the late stage, biotite dissolution still continues from the edge
and within
biotite, which results in a fine comb-like texture for weathered
biotite;
vermiculite occurs as a domain within
chemically and structurally altered biotite
as well, as at the edge even during weathering of
Mg-poor biotite.
"

So, some of the obvious experiments have been done;
replicating them on the KRS should be easy to arrange,
given the interest expressed in such testing by Uncle Sam:


http://www.lysergia.com/MerryPranksters/AcidTestBusinessCard_bw.jpg

-
Daryl Krupa

.

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