Implications of widespread high-μ volcanism on the Arabian Plate for Afar mantle plume and lithosphere composition

We report on 55 Nd–Sr–Pb and 23 Hf isotopic compositions for late Miocene to Plio–Quaternary basalts from the Arabian Plate. The sampling profile represents a 2500 km N–S transect along the Red Sea margin from Syria to Yemen. 206Pb/204Pb displays a wide range (from 18.60 to 19.55) from south to north, indicating a pervasive high-μ distribution that questions the previous attribution of this component to the Afar plume. We rather suggest that the high-μ signature resides within the Arabian lithospheric mantle. ed to basalts from northern and central Arabia (Saudi Arabia to Syria), basalts from southern Arabia (Yemen) display similar ranges for 143Nd/144Nd, 176Hf/177Hf, and 206Pb/204Pb, but are shifted towards compositions more radiogenic in Sr and 208Pb. These distinct time-integrated Rb/Sr and Th/U ratios between north and south are believed to reflect heterogeneous development of the Arabian lithosphere through time and/or result from the thermal effect of the Afar plume on the southern part of the lithosphere.