Sm-Nd and Lu-Hf isotope geochemistry of the Himalayan high- and ultrahigh-pressure eclogites

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We report multi-isotope geochemistry of the Himalayan HP and UHP eclogites. These eclogites were formed from the Permian Panjal Trap basalts. They were subdivided into Group-I and II. Group-I are HP and record P-T conditions at 704±92 ºC and 2.2±0.3 GPa. Group-II are UHP and record P-T conditions at 2.7-3.2 GPa and 757-786 ºC. The ¹⁴⁷Sm/¹⁴⁴Nd and ¹⁴³Nd/¹⁴⁴Nd and ¹⁷⁶Lu/¹⁷⁷Hf ratios and ¹⁷⁶Hf/¹⁷⁷Hf ratios in Group-I yield isochrones from 38 to 42 Ma and 45 to 50 Ma, respectively. Whereas Group-II yield 45 to 53 Ma and 42 to 48 Ma, respectively. The εNd vs. εHf plot indicates their protolith derived from ocean-island-basalts with a sediment component mixing.