Preliminary digital map of cryptocrystalline occurrences in northern Nevada

The purpose was to identify potential cryptocrystalline material sources for tools used by indigenous people of the northern Nevada portion of the Great Basin. Cryptocrystalline occurrence data combed from the U.S. Geological Survey's Mineral Resources Data System (MRDS, 1995) were combined with sites described in Nevada rockhound guides and entered into a geographic information system (GIS). The map area encompasses northern Nevada (fig.1). This open-file report describes the methods used to convert cryptocrystalline occurrence data into a digital format, documents the file structures, and explains how to download the digital files from the U.S. Geological Survey's World Wide Web site. Uses of the spatial dataset include, but are not limited to, natural and cultural resource management, interdisciplinary activities, recreational rockhounding, and gold exploration. It is important to note that the accuracy of the spatial data varies widely, and for some purposes, field checks are advised.