On diatoms:
I do not know if this is relevant or not, but how does Mr. Scott eliminate the possibility of contamination as a source of the diatoms he finds in topsoil. There are many uses for diatoms and they are mined heavily. I have used diatomaceous earth for over 20 years as a natural control for soft-bodied insects in my garden. It is a well known and has been widely used by organic gardeners for decades. I buy it in 25 lb bags at my local garden supply center.
There are many other uses of diatoms (in swimming pool filters for one) and according to this site
http://hjs.geol.uib.no/diatoms/Industry/index.html-ssi:
quote:
Diatomite or Kieselgur has been mined around the world for centuries; these deposits are either marine or freshwater and of an age between Miocene to Quaternary. The use of Kieselgur for industrial purposes relies on its extreme high porosity and low density: It is a natural adsorbent that is unparalleled.
Anyway, from my layman’s understanding, I would think that one would have to account for contamination before one could base any geological hypothesis on finding diatoms in topsoil.
Joe
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