Using the transient method, we determine the permeability of high-quartz Eleana argillite from the Nevada Test Site as a function of effective pressure. By comparing calculated and observed pressure decay in the upstream reservoir, we have determined the permeability of intact and fractured specimens at effective pressures ranging from 1.0 to 24.0 MPa. Over this pressure range, Eleana argillite has a low permeability (10{sup -16} to 10{sup -19} cm{sup 2}) when intact and a higher permeability (10{sup -12} to 10{sup -17} cm{sup 2}) with one induced through-going fracture.