(Table 1) Major and trace elements of basalts at DSDP Hole 72-516F@en

The geochemistry of basalts recovered during Leg 72 is described with emphasis on trace elements. Only Hole 516F penetrated basement; the basalts recovered are plagioclase-phyric and olivine-phyric and pervasively altered. Chemically, the basalts from Hole 516F are rather uniform in composition. However, four distinct geochemical units can be recognized, although the chemistry of two of the units appears to be controlled by chemical mobility associated with alteration. The two less-altered units cannot be related by fractional crystallization processes. Hole 516F basalts have a trace element chemistry characteristic of T-type mid-ocean ridge basalt; rare-earth element patterns (as indicated by Ce/Y ratios) are mildly fractionated flight rare-earth element enriched), and a number of incompatible element ratios are close to chondritic.本数据集描述了大洋钻探第72航次（Leg 72）采获玄武岩的地球化学特征，研究重点为微量元素（trace elements）。仅516F钻孔（Hole 516F）钻穿了洋壳基底，该钻孔采获的玄武岩均含斜长石斑晶与橄榄石斑晶，且遭受了全面蚀变。从地球化学特征来看，516F钻孔的玄武岩整体组成较为均一。不过，尽管其中两个单元的地球化学特征似乎受蚀变相关的化学活动性调控，但仍可识别出4个独立的地球化学单元。两个蚀变程度较低的单元无法通过分离结晶作用（fractional crystallization）建立成因关联。516F钻孔的玄武岩的微量元素地球化学特征符合T型洋中脊玄武岩（T-type mid-ocean ridge basalt）的典型特征；其稀土元素（rare-earth element）配分模式（以铈/钇比值（Ce/Y ratios）表征）表现为弱分馏的轻稀土元素富集特征，且多项不相容元素（incompatible element）比值接近球粒陨石值。