Are Deccan basalts contaminated by the continental crust? 

Basalts from the Western Ghats lava sequences of the ca. 66 Ma Deccan Large Igneous Province (LIP) display substantial geochemical variability from enriched, crust-like signatures in the Late Cretaceous Kalsubai and Lonavala Subgroup basalts (e.g., 87Sr/86Sri mainly 0.705-0.715) to more depleted, mantle-like signatures in the Early Paleogene Wai Subgroup basalts (generally, 87Sr/86Sri ca. 0.703-0.706). By contrast, Os isotopic compositions are relatively uniform throughout the Western Ghats stratigraphy (187Os/188Osi = 0.12 to 0.21). The lowest Os isotopic ratios are found in the Ambenali Formation of the Wai Subgroup (0.120) and may reflect a modest contribution from the subcontinental lithospheric mantle. Overall, the combined isotopic and trace-element data—particularly the Os isotopic signatures—indicate that assimilation of Proterozoic to Archean Indian crust was generally minimal (