Tin belts on the continents around the Atlantic Ocean
Tin is inhomogeneously distributed on the continents, in relatively narrow, continent-sized belts. On a reconstruction of the continents around the Atlantic Ocean before continental drift, the belts extend unbroken from one continent to another. As the ages of the tin mineralizations vary within the belts, an argument can be derived that the source of the tin and its associated elements must be in the crust. It is further speculated that concentrations of workable tin deposits occur in the intersection of orogenic belts with zones of primitive enrichment of tin. The ultimate cause of such primary geochemical culminations may well lie back in the early history of the earth.