Cpotlndf
The Cpotlndf file contains information created by Zanko, et al., (1998) but that was modified here to present only 2 classes of data in the legend and also clipped to the landform data for the major valleys. Two original classes of Zanko, et al. that contained low clay potential and insufficient information were combined and reclassed here as “Limited potential clay resources”. The other original classes of Zanko, et al. that contained Medium to High clay potential were combined and reclassed here as “Potential clay resources”. The approximate location of the main Minnesota River Valley and its major tributaries was taken from the DNR Data Deli’s Geomorphology of Minnesota layer. That layer was used to help represent where the clay layers are most likely to be close to the surface, since the rivers have eroded the upper layers of glacial drift, and exposed the buried clay layers in scattered locations. The source of this information is:
Zanko, L.M., Oreskovich, J.A., Heine, J.J., Grant, J.A., Hauck, S.A., and Setterholm, D.R., 1998, Mapping Industrial Clay Potential in the Minnesota River Valley; Report NRRI/RI-98/03 [Arcview shapefiles and tables in dbase and Access].