Wolfrrr :
Welcome to the forum.
Caliche
An accumulation of calcium carbonate at or near the soil surface. Often there are many other soils/minerals including sand , silt and clay that are in the carbonates when deposited millions of years ago including in some formations where traps exist oil and natural gas. There are in different locations around the world oil seeps at the surface which are sometimes associated with carbonates .
I think you need to start with soil samples/ cores to know what is there. In some instances one of the add ons is salt. Caliche is often associated with/is agg. lime which at to high of levels may result in alkali conditions . See link below.
http://en.wikipedia.org/wiki/Limestone My best advice is to call or email Mike Otto who is part of the PondBoss team . You may be able to find him on the forum. Try him at email below or send him a private message his member # is 1570 or call the PondBoss office see second link below.
mikeotto@ntin.net
http://www.pondboss.com/ ewest