Fig. 3
From: Enhanced flux of extraterrestrial 3He across the Permian–Triassic boundary
Results of the stepwise heating experiments. 3He (a) and 4He (b) release profiles as a function of temperature for sample NF-37B. 3He/4He ratios for NF-37B are shown in each panel for comparison. Helium extracted at 850 °C yielded a high 3He/4He ratio (14 Ra), suggesting release from IDPs. The stratigraphic level of sample NF-37B is shown in Fig. 2