Stable hydrogen and oxygen isotope ratios for selected sites of the U.S. Geological Survey's NASQAN and benchmark surface-water networks

Increasingly, hydrologic studies require information on the isotopic composition of natural waters. This report presents stable hydrogen (delta2H) and oxygen isotope ratios (delta18O) from 391 selected sites of the U.S. Geological Survey's National Stream Quality Accounting Network (NASQAN) and BENCHMARK surface water networks collected during the years 1984 1987. Depth-integrated samples were collected and analyzed from each site bimonthly or quarterly for about 3 years.