Argon and helium content of the atmosphere coupled with the Earth's thermal evolution

抄録

The interconnection between the dissipation of radiogenic ⁴He and ⁴⁰Ar from the Earth's crust and mantle and the Earth's thermal evolution is considered. A model coupling the ⁴He and ⁴⁰Ar dissipation from the mantle with the zone melting in the upper mantle is proposed. The input functions in analytic form for ⁴He and ⁴⁰Ar flows into the atmosphere are followed by the solution of the Earth's thermal evolution. The solutions are given for cases describing multiple mantle melting under continents and, perhaps, single melting under the oceans. These solutions are in good agreement with the ⁴⁰Ar economy in the atmosphere and the flow of modern ⁴He into the atmosphere. Probably about 60% of the modern ⁴⁰Ar abundance dissipated to the atmosphere during the first melting cycle.