High 3He/4He in central Panama reveals a distal connection ...
Nov 23, 2021 · For example, considering that the mantle beneath Costa Rica (3 He/ 4 He CR) has a 3 He/ 4 He ≥ 8 R A, the maximum ( R A) and average ( R A) 3 He/ 4 He values in geothermal fluids <70 °C require crustal He contributions of >14 and >66%, respectively (SI Appendix, Figs. S6 and S7).