Some of the largest concentrations of lead and zinc are located in the midwestern states of the US. The Tri- State district of Oklahoma, Missouri and Kansas and the southeastern Missouri Viburnum Trend share several geological similarities, which have not only produced the minerals mentioned above but museum-quality examples of sphalerite, calcite and galena.
AN OVERVIEW
The Midwest contains two of the greatest concentrations of zinc and lead in the world. These are the Tri-State ...