Ah caliche, caliche you say tomato, I say tomato.
I think it would take a geologist to tell the difference between some of the natural caliche you find, and some of the lime based plasters and cements used by the advanced Indian peoples; the Aztecs and Mayas both burned lime for lime plaster and a form of cement, and there are ancient lime kilns (for burning lime to make quicklime, a critical ingredient for cement and plaster) located along the Salt river valley. These kilns are sometimes mistaken for primitive metal foundries, but the lack of any slag helps give them away. So there is evidence that local (Hohokam) may well have been making lime plaster or a type of cement, which after time and weathering would be very difficult to tell from natural caliche which is basically much the same thing only naturally formed. Just my
amateur opinion, but I don't think we can tell for certain just by looking at photos. Please do continue....
Oroblanco
Roy:
Some good info on Mayan construction within this series of lectures......
http://www.newmedia.ufm.edu/gsm/ind...Technology_in_the_Cradle_of_Maya_Civilization