Compilation of isotopic and fission track age determinations, some previously published. Data for the tephrochronology of Pleistocene volcanic ash, carbon-14, Pb-alpha, common-lead, and U-Pb determinations on uranium ore minerals are not included.

Geologic map unit and lithologic descriptions used in Open File Report 2005-1235, with extensive bibliographic references to geologic literature that could not be included in the spatial database.

The spatial databases represent the original content of 43 published geologic maps, provide normalized map unit descriptions, and provide additional information and interpretation not in the original reports.