|Description||This dataset was digitized by the U.S. Geological Survey EROS Data Center and U.S. Geological Survey Spokane Field Office for input into an Arc/Info geographic information systsem (GIS) The digital geologic map database can be queried in many ways to pro|
|Originators||Harrison, Jack E.; Griggs, A. B.; Wells, J. D.; Kelley, W. N.; and Derkey, Pamela D.|
|Publication||U.S. Geological Survey Miscellaneous Investigations Series Map I-1509-A|
The "Geologic and structure maps of the Wallace 1°x2° quadrangle, Montana and Idaho: a digital database" report (wal250k.pdf) contains a detailed description of each attribute code and a reference to the associated map symbols on the map source materials. The database includes a geologic linework arc attribute table, wal250k.aat, that relates to the wal250k.con (contact look-up table), wal250k.st2 (structure look-up table), wal250k.lgu (linear geologic unit look-up table), and wal250k.ref (source reference look-up table) files; a rock unit polygon attribute table, wal250k.pat, that relates to the wal250k.ru (rock unit look-up table) and wal250k.ref (source reference look-up table) files; and a breccia point attribute table, wal250bc.pat, that relates to the wal250bc.ref (source reference look-up table) files.