The diat. potential energy function for helium has been detd. via the inversion of reduced viscosity collision integrals at corresponding states and zero pressure. The resulting potential has been fitted to obtain an anal. form. A comparison...

that the methane likely formed prior to the infiltration of hypersaline Silurian seawater. The methane has since remained in place, making it, perhaps, the oldest documented occurrence of biogenic methane. This is consistent with helium isotope data, which also...