Annotated record of the detailed examination of Mn deposits from DSDP Leg 82 (Holes 556, 558, 559, 562, 563, 564)

One of the most important geologic discoveries of the 1960s was the remarkable uniformity of the basalts produced at mid-ocean ridges. These basalts have a markedly different tholeiitic composition compared to the alkalic basalts from ocean islands. But very little is known about temporal variations in the composition of basalts derived from one or several mantle sources associated with both normal and anomalously shallow sections of the mid-ocean ridges. The strategy for drilling on DSDP Leg 82 was to set up a broad grid encompassing all possible drilling sites west and southwest of the present Azores Triple Junction in order to investigate these problems.

20世纪60年代最重要的地质学发现之一，便是洋中脊（mid-ocean ridges）产出的玄武岩具有显著的均一性。此类玄武岩的拉斑玄武岩（tholeiitic）成分，与洋岛碱性玄武岩存在显著差异。然而，针对与洋中脊正常及异常浅剖面相结合的单一或多个幔源所形成的玄武岩，其成分随时间的变化规律目前仍鲜为人知。深海钻探计划（Deep Sea Drilling Project, DSDP）第82航次的钻探策略，是在当前亚速尔三联点（Azores Triple Junction）的西侧与西南侧布设覆盖所有潜在钻探位点的宽网格，以对上述科学问题展开研究。