资源环境科技发展态势分析平台

Based on biomarkers and bulk organic carbon isotope, we reconstructed a 5-million-year history of terrestrial material input to the northwest shelf of Australia. Vegetational organic input continuously decreased through the Pliocene-Pleistocene period due to decreased vegetation coverage and discharge under general aridification process. Triggered by lowered sea level and drier climates, soil input increased after ∼2.5–2.2 million years ago (Ma). Bulk terrestrial organic input demonstrates stronger variability after ∼1.7 Ma, as influenced by large-amplitude hydrological swings on the Australian continent. Source of soils shifted between ∼1.5–1.2 Ma, along with presence of active dune fields. All lines of evidence together indicate a general wet climate in northwestern Australia during the early Pliocene, a continuously drying trend to the mid-Pleistocene, and a drier phase with less vegetation coverage and expanded desert during the late Pleistocene, which is modulated by ongoing Indonesian Throughflow constriction and global atmospheric circulations.