The results of our study suggest that garnet is probably one of the most retentive silicate minerals for He, which is in agreement with its very low ion porosity.
The high retentivity results in a high closure temperature (T lies between 590° and 630°C.
Accordingly, (U Th)He dating of garnet may provide information about the medium to high temperature cooling path of a rock at the lower end of the temperature range of currently used isotopic systems in garnet.
The second step-heating pyrolysis of the coral using 50°C-steps indicated that all He amount was 2.27 x 10-8 (±0.04% 1σ) cc STP/g, yielding an age of 83 ka, again lower compared to that obtained by U-Th disequilibrium. Radiogenic U incorporated into carbonates is a potential chronometer of Quaternary, and possibly Tertiary, corals and speleothems.However, several limitations exist for this method, related to the few data on the He diffusion  and on the alpha recoil effect in carbonate minerals.Creationists now have done their own experimental research that calls this assumption into question.The research on Helium diffusion in zircon crystals that follows is one line of evidence to that effect.