Oxford University Recorded Background Seeps25 Jan 2024 07:48
Were
"The Itumbula and Ivuna seeps, within RBB, have the highest 4He concentrations (2.4 Γ 10-2 and 6.9 Γ 10-2 cm3 STP/cm3 (2.4-6.9%) and have radiogenic helium."
For proof google.
The origin of high helium concentrations in the gas fields of southwestern Tanzania
20x that background level sounds like a motherload to me πππ