Figure 3

Eu/Eu* (a) and CaO (b) versus MgO for Site U1500 basalt samples. In (a), elemental anomalies are calculated as follows: Eu/Eu* = Eu_N/(Sm_N × Gd_N)^0.5, N here stands for chondrite normalized. In (b), the gray dotted line separating pyroxenite melts from peridotite melts is from Herzberg and Asimow⁵³. Lavas with CaO contents lower than those defined by the dotted line are potential pyroxenite-bearing partial melts. Reference data for basalt samples from Sites U1431 and U1433 are referred to references^10,14. In (b), the calculated primitive melt compositions for Site U1500 basalts are shown in red circles while calculated primitive melt compositions for Site U1431 are shown in grey diamonds. Average elemental data for N-MORB and E-MORB are from Gale et al.⁶⁰. Data for global MORB (Pacific Ocean MORB and Indian Ocean MORB) are derived from Petrological Database (http://www.earthchem.org/petdb). Symbols are the same as in Fig. 2.