Geochemical Perspective on Provenance and Tectonic Setting of Late Carboniferous–Early Permian Siliciclastic‐Carbonate Rocks of South Yellow Sea

ABSTRACT The South Yellow Sea Basin siliciclastic‐carbonate successions provide an important chance to establish the provenance and tectonic environment along the eastern edge of the Lower Yangtze Platform. Herein, an integrated data set of major and trace elemental concentrations and systematic distribution of rare earth elements (REE) for the Late Carboniferous–Early Permian succession to study the robustness of provenance proxies under strong carbonate dilution and constrain the tectonic environment of deposition. PAAS‐normalized REE shows a uniform LREE‐enrichment with flat HREE segments and Eu/Eu* ≈ 1, whereas ΣREE shows positive correlations with Al 2 O 3 and TFe 2 O 3 and negative correlations with CaO, verifies the presence of aluminosilicates and Fe phases as the dominant REE hosts, and carbonate dilution is the other controlling factor on absolute ΣREE. The stratigraphic gradient of Ce/Ce* is a strongly negative range in Chuanshan‐Huanglong formations (open marine shelf), to a near‐unity range in the more terrigenous Gaolishan Formation. Immobile element ratios and fractionation indices (e.g., La/Sc, Th/Sc, La/Co, Th/Cr, (La/Lu)n, (Sm/Yb)n) are invariable over a broad range of the major oxide concentrations (excluding Ca, Mn and P), and discrimination diagrams (Th‐Sc‐Zr/10, La/Y‐Sc/Cr) consistently give evidence for granitoid, upper continental crust sources, as well as multi‐cycle sediment recycling with tiny mafic input. A further argument in favour of open‐marine to outer‐shelf environment on a subsiding passive continental margin is combined Eu/Eu*‐Ce/Ce* and LILE ternaries. The geochemical signatures we document are consistent with regional seismic and depositional structural observations, supporting the view that the South Yellow Sea Basin first formed as a passive cratonic margin before Indosinian inversion. This integrated evidence also provides a practical basis for using REE and trace‐element indicators to reconstruct the basin's tectonic evolution in mixed siliciclastic carbonate successions.