Triassic depleted lithospheric mantle underneath the Paleozoic Chinese Altai orogen: Evidence from MORB-like basalts

Whole-rock geochemical and Sr–Nd–Pb–Hf isotopic analyses were conducted on the Triassic Ashele post-orogenic basalts from the Chinese Altai. The tholeiitic Ashele basalts possess moderate Na2O (2.46–4.52 wt%) but extremely low K2O (≤0.06 wt%) contents, and are depleted in light rare earth elements (LREE). Their (La/Sm)N and (La/Yb)N ratios range from 0.78 to 0.88 and from 0.72 to 0.84, respectively, which, together with their low initial...