Fig. 7
From: Enhanced flux of extraterrestrial 3He across the Permian–Triassic boundary
Extraterrestrial 3He (3HeET) flux and radiolarian species diversity across the PTB. a 3HeET flux calculated from extraterrestrial 3He concentrations (Table 1), a mean dry bulk density of 2.6 g cm−3 for claystone, and mean sedimentation rates calculated using astronomically tuned cyclostratigraphy. Error bars are based on two standard deviations calculated for the MAR of the Permian section. The 3HeET flux after the MEE horizon was tentatively estimated assuming sedimentation rates remained stable after the MEE. See Table 1 for data. b Stratigraphic variation of the number of Permian radiolarian species in the study section (Sano et al. 2012a). Marked decline in the diversity of Permian radiolarians began at ~ 500 kyr prior to the PTB. Permian radiolarians in the Triassic section are regarded as reworked species (Sano et al. 2010)