Annotated record of the detailed examination of Mn deposits from DSDP Leg 69 (Holes 504 and 504B)1982

The sites 504 and 505 of Deep Sea Drilling Project Leg 69 were selected for the purpose of investigating geothermal phenomena in basaltic basement and overlying sediments at two locations in the same segment of an oceanic spreading center-the Costa Rica Rift. Two additional experiments were conducted in Hole 504B to measure the bulk properties of the ocean crust: the large-scale resistivity experiment and the oblique seismic experiment.为探究洋中脊扩张中心同一分段内两处点位（哥斯达黎加裂谷区域）的玄武岩基底及上覆沉积物中的地热现象，本次研究选取了深海钻探计划（Deep Sea Drilling Project）第69航次的504与505站位。此外，还在504B号钻孔（Hole 504B）中开展了两项额外实验，以测定洋壳的整体物性：大尺度电阻率实验与倾斜地震实验。