Systematic Variation of Sr, Nd and Pb Isotopes with Time Observed in lavas of Mauritius Island

The active volcanism of the Reunion mantle plume began with the emission of huge volumes of flood basalts of the Deccan Traps at the end of Cretaceous. Subsequent products from this hotspot can be traced on the seafloor of the Indian Ocean. We report Sr, Nd and Pb isotopic compositions for the rocks of Mauritious Island which is the second youngest Island by the Reunion hotspot activity. The lavas of the older series (8 - 5.5 Ma) seems to be directly related to the hotspot, and showed the limited range of Sr isotopic composition from 0.70411 to 0.70422, which is consistent with those of Reunion Island (2Ma - present). Via Intermediate series volcanism (3.5 to 2.0 Ma), the Younger stage lavas ( 0.7 to 0.2 Ma) show slightly depleted isotopic signatures. Systematic variations of these isotopes with time can be attributed to the change in the structure or composition of the mantle from the less depleted to the more depleted, more MORB-like signature. The present variations are correlated with those of Hawaii and French Polynesia, but the trace elements distributions are not identical with them.