Abstract The Mesoproterozoic (ca. 1.6–1.0 Ga) is primarily characterized by pervasive tectonic stasis under greenhouse climate. However, the coeval weathering regime still remains elusive. Here, we conduct comprehensive investigations (including detrital δ7Li values, elemental compositions, and clay mineral assemblage) on the 1.4‐billion‐year‐old iron formation (IF) hosted shales from the Xiamaling Formation to reconstruct coeval detailed continental chemical weathering history. Our results show a −3.5‰ δ7Li excursion, in comparable to Paleocene–Eocene Thermal Maximum, and notably high chemical index of alteration (CIAcorr) values (>80) during the deposition of IF. This intensification of continental chemical weathering was probably triggered by increased exposure of easily weatherable rocks in the tropics. Furthermore, the enhanced nutrients availability, resulting from enhanced continental weathering, could have boosted marine primary productivity, thereby facilitating increased organic carbon burial and atmospheric oxygenation.
Observations from the Little Bunker
Last updated: August 18, 2025 04:13 PM
Atmospheric CO₂
425.4 ppm
+18.4
ppm/year
Atmospheric CH₄
1934.91 ppb
+9.11
ppb/year
Global Temperature
+1.48 °C
Peak: +1.73°C
World Population
8.1 billion
+67
million/year