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

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。与来自大洋岛屿的碱性玄武岩相比，这类玄武岩具有显著不同的拉斑玄武质（tholeiitic）成分特征。然而，针对源自与洋中脊正常及异常浅段相关的单一或多个地幔源区的玄武岩成分的时间变化，目前学界的认知仍十分有限。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）以西及西南区域构建覆盖所有潜在钻探点位的大范围网格，以针对上述科学问题开展研究。