Figure 17. A spidergram for a basalt clast from interval 149-899B-31R-1, 9-14 cm, normalized to primitive mantle and the five common basalt provinces for comparison and source determination. The less mobile elements on this spidergram display a more irregular pattern than the other basalt clasts, with the HFSEs Zr, Hf, and Ti all having negative peaks. In addition, the usual seafloor weathering peaks are present with positive Rb and K peaks and a negative Sr peak. As usual, the strong Nb-Ta peak relative to the IAT spidergram indicates this clast is not from an island-arc.