Insights on the Cenozoic climatic history of Southeast Australia from kaolinite dating

Australia hosts some of Earth's oldest regoliths. They were preserved through geological time thanks to exceptionally low erosion rates affecting large parts this continent. Accurate chronological constraints about their formation and evolution are abundant in its northern western regions. However, they remain underexplored southern eastern parts, limiting our knowledge the extent impact Cenozoic hot wet paleoclimatic events over To address question, we provide a new set data obtained from tropical regolith southeastern Australia, close side Australian Great Escarpment (Syerston–Flemington, New South Wales). The Syerston regolith, known for anomalous Sc content, exhibits thick duricrust (18 m deep) comprising an situ detrital component. thickness these indurated horizons presence protecting lower profile secondary weathering favourable conditions conservation long-term record paleoweathering history. Electron Paramagnetic Resonance (EPR) dating phyllosilicates allows discrimination two generations kaolinite formed at 10.1 ± 2.3 Ma 3.8 0.9 Ma, trapped within duricrust. In parallel, horizon with age 8.2 2.8 1 0.3 top. Such ages confirm hypothesis that, following end Middle Miocene period, Late climate southeast was still development covers. These results, combined other studies literature, suggest that part extended coastal regions suffered warm Mid-Miocene beginning Miocene. hypothesis, as well Central during Late-Miocene, period onset aridity, need be constrained by complementary paleoregolith studies.