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Dear Editor,
The March-April Microseep carried my letter along with Dr. Klusman's
response. Dr. Klusman correctly decribes my 1986 mechanism and poses a number of questions concerning iodine. I will address his questions.
1. Halos/Apical
Dr. Klusman is correct that we (Atoka) have changed from a
halo (1990) to an apical model for most new fields. We are
currently editing a paper that will demonstrate some of the
reasons for this change.
2. Sample Stability
Most soil iodine "background" samples are stable for years.
However, some of the soil iodine, much of which is the iodine
above background, is less stable and measurably declines over a
period of less than a year. It is not a single compound and is
not a linear decay.
3. Unlabeled Table
The Table in Alexan et al. was derived from data found in the
"Handbook of Chemistry and Physics".
4. 7800 Angstroms
Dr. Klusman's final question is puzzling. In 1986 I was very
deliberate in the choice of the word "theshold" to make it
clear that 7800 angstroms was a "minimum energy" and higher
energies would also break this bond. Also in a letter to him
dated December 9, 1993, I wrote "I agree completely that most
of the energy will be provided by visible and ultra-violet
light, and that 7800 angstroms is a minimum." Grover and
Willard (1960) recommend 1849 anstroms for maximum iodoorganic
yields, about 1000 angstroms shorter that the ultraviolet
penetrating to the surface. The available light capable of
breaking these bonds ranges then from about 2700 angstroms to
7800. The mechanism is entirely consistant with organic
and atmospheric chemistry.
Sincerely,
Chuck Goudge
Atoka Exploration Labs
Note: Mr. Goudge is now with GrayStone Exploration Labs in Golden, Colorado.
Dear Editor,
Mr. Chuck Goudge's letter of April 29 adequately clarifies the
role of ultraviolet light in the formation of iodo-organic
compounds in surface soils. However, I remember on at least
two occasions in the past that Atoka personnel indicated that
infrared radiation was required.
I still maintain that the iodine method could benefit from some laboratory experimentation on the formation of these compounds followed by some closely controlled field experimentation where where active microseepage is known to be occuring. An analysis of variance experiment, where a series fo plywood panels arranged in a checkerboard pattern, just above the surface, to block ultraviolet light, but not attenuate other microbial processes will accomplish this. The organo-iodine content of soil before and after a period of time under the panels, and in the exposed areas between the panels, could substatiate the process. The experiment would require an appropriate statistical design to evaluate sampling and analytical error separately in order to test whether iodine content was different under panels, compared with alternate areas which are exposed to sunlight. The experiment should be done "blind" with the samples submitted to the laboratory in a random order.
If Atoka can provide an experimental location and fund the project, I would be willing to design the experiment, sample the soils according to their protocol, submit them for analysis in their laboratory, and interpret the results. The results of the experiment could potentially be suitable for a co-authored publication in the APGE Bulletin.
Sincerely,
Ronald W. Klusman
Colorado School of Mines