Methane-concentration and methane-isotope data for ground water and soil gas in the Animas River valley, Colorado and New Mexico, 1990-91

Abstract

In this report "sea level" refers to the National Geodetic Vertical Datum of 1929 (NGVD of 1929) a geodetic datum derived from a general adjustment of the first-order level nets of both the United States and Canada, formerly called Sea Level Datum of 1929.