Founded in 1982  GrayStone Exploration Labs has a data base of more than 350,000 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 underlying deposits.
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, we have detected a 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.
Iodine Questions
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? In some ways it may be better, many tools have
certain advantages that are unique, iodine is one of the best general 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 but natural rock salt has almost no
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.
Exploration Philosophy
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 the soil 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
Much of the data base is from North America and the United States. Our goal is to always  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