Helium flux from a sedimentary basin

The tritium-He-3 ages of groundwaters collected from the Saijo Basin in Jap an were measured. The ages vary between 11.7 and 16.3. years. The He-4 flux of > 3 x 10(4) atoms/cm(2) s is calculated by the He-4 concentrations and ages. In addition the helium flux of 8.3 x 10(5) atoms/cm(2) s is calculate d at like Higashi-Niigata gas field in Japan. The above two estimates are c onsistent with the continental helium flux reported in the literature, sugg esting that helium flux on the Earth's crust is uniform. (C) 2000 Elsevier Science Ltd. All rights reserved.