This report includes previously written, but unpublished descriptive industrial mineral deposit models not released in earlier reports (Cox and Singer, 1986; Orris, 1992; Orris and Bliss, 1991, 1992). Although some of the models are preliminary, recent and repeated requests for several of the models has led to their release in this compilation. Initial drafts of the clay models were written for individual U.S. deposits or districts by J.W. Hosterman2 of the U.S. Geological Survey (USGS) in the late 1980/s. All of the models in this report have been modified from their original unpublished versions; for most models, the modifications have consisted of additional geologic detail, economic information, and (or) health and environmental considerations related to the deposit type. More extensive alterations have been made to the clay models written by Hosterman, which were put into standard format and extensively revised by G.J. Orris. As much as two-thirds of the information in the current versions of the models post-dates Hosterman's contributions and these models are shown as jointly authored.
