0 10203040506070809010 columbium mica sheet strontium manganese bauxite asbestos platinum group tantalum tungsten tin barite cobalt chromium potash nickel antimony cadmium zinc selenium aluminum gypsum iron and steel ore sulfur copper 682 natural resources figure 24 1 net us imports of selected minerals metals as a percent apparent consumption 1994 source chart prepared by bureau the census for data see table 1154 section this presents on area ownership production trade reserves disposition nat ural is defined here includ ing forestry fisheries mining mineral products timber resource com mercial timberland statistics cov ering national forests forest service cooperative programs product lumber pulpwood woodpulp paper paperboard similar principal sources relating to are an analysis situation in united states 1989 2040 1990 re 1992 1993 consump tion price land areas system issued annually department