So . . . "geoneutrino" is the new name for the antimatter neutrino which "are thought" to originate withing the earth versus elsewhere throughout the cosmos. Other than "thinking", they don't mention how the origins of the two particles is determined. We're somewhere off in the realm of speculative science wherein all sorts of theories, such as evolution, reside that never seem to get corroborative evidence other than "are thought", "could have been", "are supposed" and other equally relevant scientific terms.