Fig. 3
From: Orbital eccentricity and internal feedbacks drove the Triassic megamonsoon variability
Comparison of fossils and sedimentary environments in the Ordos Basin with global and regional geological records during the Middle Triassic. (a) Fossil assemblages found in North China and South China. Names: T = Tongchuan Biota51, Y = Yonghesuchus (241.48 ± 0.13 Ma)52, S = Sinokannmeyeria (243.53 ± 0.13 Ma)52; X = Xingyi Biota (240.65 ± 0.69 Ma)53, P = Panxian Biota (243.4 Ma)54, L = Luoping Biota (243.8 Ma)54. (b) depositional environments at Yaoye-1. DL deep lacustrine subfacies, SL shallow lacustrine subfacies, DF delta facies. (c) Fe/Ba data series. The thick gray line is the 1,000 kyr “moving” trend of the (gray dots) measured values. (d) Sequence stratigraphic cycles from the Arabian Platform55. MFS maximum flooding surfaces. (e) Compilation of sea surface temperature during the Middle Triassic based on conodont apatite δ18O record56. The solid black line represents the Locfit analysis of δ18O data, with dashed lines bracketing the ± 95% confidence interval. (f) Integrated carbonate δ13C of marine Sections57,58,59. (g) Silicate weathering rate from BSi flux in the pelagic Inuyama section, showing a discerned ~ 3.3 Myr cycle19,20. (h) Conodont apatite 87Sr/86Sr record60,61. (i) Comparison of multi-Myr cycles in geological records and astronomical solutions during the Triassic. Wavelet analysis of astronomical solution La2010d eccentricity (top panel)32 indicates that the wavelet amplitude (red for peaks; blue for valleys) within the ~ 100 and 405 kyr eccentricity frequency bands is modulated by a period of ~ 3.3 Myr for the Middle Triassic. Wavelet analysis of δ18O data series56 and evolutionary spectra of δ13C and BSi flux data series20 reveal significant ~ 3.3 Myr cycles during the Middle Triassic in both the δ18O and BSi flux data series.
