Figure 12. A spidergram for a basalt clast from interval 149-899B-27R-1, 19-26 cm, normalized to primitive mantle and the five common basalt provinces for comparison and source determination. This clast is slightly trace-element enriched relative to N-MORB and slightly depleted relative to E-MORB, which fits a transitional MORB source province. It contains unusually large Nb-Ta peaks relative to the typical Nb-Ta-depleted IAT spidergram. The enrichment in elements Rb, K, Sr, Eu, and Ba is unusually pronounced. Enrichment in Rb, Ba, and K is attributed to seafloor weathering, whereas enrichment in Sr and Eu is probably related to the plagioclase phenocrysts in this clast. Normalization values are from Sun (1989), Sun and McDonough (1989), and others as discussed in the text.