Geochemical analysis of rock samples collected and analyzed by the USGS. This dataset includes and supersedes rock data formerly released as "Geochemistry of igneous rocks in the US extracted from the PLUTO database". The database contains 414,304 records.
Get the entire data set:
ngdbrock.zip (zipped shapefile with sample ID and link to online report 7.2M bytes)
ngdbrock-tab.zip (tab-delimited text, one file per table 36M bytes)
download (DBF files, zipped, downloadable separately 50M bytes total)