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understanding laterite

I dont know if this is of interest to anybody but me, but I have been on
a quest to learn what laterite exactly is and where it comes from. I
have always thought the term was over used to describe just about any
type of clay. What I have learned would suggest that there is no such
thing as north american laterite. If this is old hat to anybody on this
list, I apologize. I will briefly describe what I have learned and then
pose a question. If anyone would like to add something to this or tell
me I am incorrect please do so.

I have spoken by email to three diffrent geological university
professors. The short of it is that laterite is a term for lateric soil.
Lateric soil has been exposed to continous tropical heat and rain in an
open area that strips the soil of all nutrients leaving only high
amounts of Fe3+ and aluminum oxides. Laterite is formed from the
weathering of basalt. Terrestrial plant life can not grow in laterite.
One professor told me the concentrations of unusable Fe3+ are so high
that the soil is incapable of holding any other nutrients and has no
CEC. Lateric soil is also a serious problem caused by strip mining and
rain forest deforestation. (pardon my spelling).

Laterite soil happens only where there is both tropical heat and heavy
tropical rains. South America, carribian, and tropical asia. All three
profesors stated to me that the only place in north america where this
could occur is in Florida, but they are unaware of any laterite areas in
that swampy state.

So my question is, the companies in North America that claim to make
laterite product here, where is this laterite coming from? Is it true
laterite or something else?  I guess I am reffering to Substrate Gold
and a product called Aquarium Plant Spikes made by Agsafe, sold by
Arizona Aquatic Gardens. Soils from outside the USA are supposedly
banned from import into the USA.

The university professors were kind enough to answer my questions, but I
dont think they would appreciate me broadcasting their email addresses.
But here is one site that gives a brief description:

from one proffessor: "If you would like a response from a whole group of
clay minerals scientists who are much more expert than I on soils, you
can broadcast your inquiry to their server at


Robert H