Annotated record of the detailed examination of Mn deposits from DSDP Leg 63 (Holes 468B, 469, 470, 470A, 471, 472)

A primary objective of Leg 63 was to investigate the fluctuations of this eastern boundary current along a north-south transect off the Gulf of California. This information would aid in biostratigraphically correlating open-ocean planktonic zones with local California zonations. Spanning the last 30 m.y., the complicated tectonic history of the continental margin off California and Baja California comprises changes from a subduction zone to a transform boundary and then to an inactive margin. A second objective of Leg 63 was to define and clarify this history using information on sedimentation, unconformities, basement ages, and paleomagnetic reconstructions gained from drilling, in conjunction with geophysical data and pre-existing bottom samples.

大洋钻探第63航次（Leg 63）的核心目标之一，是探究加利福尼亚湾沿岸海域的东边界流（eastern boundary current）沿南北向断面（north-south transect）的波动特征。该研究数据将助力实现远洋浮游生物带与当地加利福尼亚生物带的生物地层对比。加利福尼亚与下加利福尼亚沿岸大陆边缘的构造演化历史极为复杂，时间跨度覆盖过去30百万年，其经历了从俯冲带（subduction zone）至转换边界（transform boundary），再演化为不活动大陆边缘（inactive margin）的构造变迁过程。本航次的第二项核心目标，是依托钻探获取的沉积作用、不整合面（unconformities）、基底年龄（basement ages）及古地磁重建（paleomagnetic reconstructions）数据，结合地球物理资料与已有海底样品，明确并厘清该段构造演化历史。