Founded in 1982 GrayStone Exploration Labs has a data base of more than 365,000 soil samples
analyzed for iodine and other components. Most are for oil and gas geochemical exploration surveys
but also include surveys for uranium and gold. Samples have been analyzed from Europe, Asia,
Australia, North and South America, and a number of islands.
Frequently Asked Questions
General Geochemical Questions
1) What is Surface Geochemistry? The detection of hydrocarbons, at the surface, which have leaked from
3) Do hydrocarbon deposits really leak? Yes, most of them. Although seismic dominates exploration now,
prior to the 1930's, most oil was found by tracking oil seeps, Tracking invisible micro seepage using
analytical chemistry is a natural extension of this very successful exploration method.
4) Does this only apply to shallow deposits? No, I have detected a strong surface signature for an oil
deposit at more than 10,000 feet, and other researches have reported successful detection of leakage from
even deeper sources.
2) Can I use geochemistry everywhere? No, some environments are to extreme to use some tools.
1) What does iodine have to do with hydrocarbons? Many different elements become involved in the
oxidation processes surrounding the leaking hydrocarbons. Iodine is a very reactive element and has a
tremendous affinity for organic compounds. Iodo-organic compounds accumulate In areas of seepage. See
2) Is iodine as good as other geochemical methods I have heard about? I believe it is better, iodine is
one of the best and most versatile geochemical exploration tools.
3) Does rain wash it away? No, the compounds produced by the combination of the hydrocarbons and
iodine are insoluble.
4) Does road salt cause a problem? No, iodine is added to table salt to prevent goiter as natural rock salt
contains almost no iodine.
5) Why do you sample the surface, wouldn't soil a few inches or feet down be better? No, soil is a very
complex system and the only place in the soil profile that you can be certain of is the very top of the A
horizon. Arbitrary sampling depths measure a variety of unknowable subsurface conditions. Also the surface
allows the integration of multiple sample locations for each measurement.
1) Why don't you offer hydrocarbon methods? I have never been convinced that hydrocarbon techniques
are as good as iodine and other soil modification techniques. Hydrocarbons are volatile, reactive and difficult
to contain and measure. The retention, flux rate and complex chemistry of hydrocarbons in soils have
barely been investigated much less quantified.
2) How many samples should I take? The simplest answer is; as many as you can. Sample density is the
most important factor for successful geochemistry. Think of samples as pixels in a picture, the more pixels
the better the picture. This analogy also demonstrates that the quality of each pixel, or in this case the
number of sample measurements or sophistication of the analysis, does almost nothing to resolve the larger
picture. This is why my use of a low cost technique spread over a large number of samples has been
more successful than the more complex and expensive geochemical techniques using fewer samples.
Much of the data base is from North America and the United States. Our goal is to always to
provide the best data possible and to continuously improve the quality and value of our surveys.
Geochemical Exploration Services
GrayStone Exploration Labs, Inc
GrayStone Exploration Labs, Inc