Extended Data Fig. 8: Sensitivity of our calculations to the choice of slope and intercept of the Paleocene MWL for Tibet.
From: High-elevation Tibetan Plateau before India–Eurasia collision recorded by triple oxygen isotopes
a. Contours of the oxygen isotopic composition of the calculated palaeo-meteoric water assuming 240 °C formation temperature (as in Fig. 2a) for plausible range in MWL slopes (λ) and intercepts (γ). The modern MWL slope and intercept estimates from previous work (global and regional) mentioned in the text are shown by grey points (BL10: Luz and Barkan28; PJ19: Passey and Ji30; A20: Aron et al.27). The error bars on the mean values for the Tibet MWL are 1σ as reported in the text (and shown in Extended Data Fig. 1a) and propagated in our calculations. The light blue symbols are the seasonal and annual slope and intercepts from the Tian et al.25,70 dataset from Lhasa and Nyingchi. With seasonal slopes derived for a more extensive region by Tian et al.25 (Qinghai-Tibet Plateau; see their Table 3) shown across the top of the plot. b. Same as panel a but for the mean palaeoelevation estimate using the model of Rowley and Garzione22 as in Fig. 2b. The purple zone illustrates the postive relationship between the seasonal slopes and intercepts derived in this study and the global meteoric water lines reported by previous work24,25,27. Confidence shading is 1σ in both panels.
