Crustal Block Rotation in a Migrating Transform Zone: Oriented Piston Cores Study

迁移转变带中的地壳块旋转：定向活塞芯研究

• 批准号: 8922977
• 负责人: Martin Kleinrock
• 金额: $ 2.22万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-05-01 至 1991-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8922977&HistoricalAwards=false
• 关键词: Crustal; Block; Rotation; Migrating; Transform

Much of Dr. Kleinrock's research has focused on mechanics ofthe now-classic propagating spreading center at 95.9'W on the East Pacific Rise. An oddity of this and all propagators is the ocean crust gets transferred from one lithospheric plate to another as the "active" spreading axis advances into and splits the "old" crust. Complex deformation patterns are known to develop between the active and inactive spreading centers. Two theories exist to explain this deformation: 1) the "deck of cards model" that predicts displacement is accomodated along pervasive ridge-normal faults: and 2) the "bookshelf tectonics" model that predicts deformation is taken up by crustal block rotation about vertical axes. Dr. Kleinrock will test the latter by examining piston cores for down-core rotation relative to the earth's magnetic field. During a recent cruise, he supervised the acquisition of 6 piston cores within the regions of suspected deformation at the 95.5'W system. Each was equipped with a corehead camera to record obsolute orientation, rotation, and departures from vertical that occured during the coring process. Dr. Lisa Tauxe at Scripps will conduct full-core, pass-thorough cryogenic magnetometer measurements on these cores. When split, subsamples will be analyzed for remnant magnetization, Inclination and declination values derived from these analyses will be provided to Dr. Kleinrock who will then incorporate the corehead information to remove corring artifacts to construct a down-core history of absolute rotation for each core. He estimates that at least 45' of block rotation has occurred in the region, and the technique proposed here will be able to resolve rotations of roughly 10'.

Kleinrock博士的大部分研究都集中在力学上 东95.9 'W为典型的传播扩散中心 太平洋崛起海洋是这一切传播者中的一个异类 地壳从一个岩石圈板块转移到另一个 "活跃"的扩张轴进入并分裂"旧"的扩张轴， 地壳。已知复杂的变形模式在 活跃和不活跃的扩散中心。有两种理论 解释这种变形：1）"扑克牌模型"， 预测位移是适应沿着普遍脊正常 断层：2）“书架构造”模型，预测 变形由地壳块体绕垂直方向的旋转来承担 轴。克莱因罗克博士将通过检查活塞来测试后者 相对于地球磁场进行向下核心旋转的核心 领域在最近的一次巡航中，他监督了6架 活塞芯在怀疑变形的区域内， 95.5'W系统。每个都配备了一个核心摄像头， 绝对的方向，旋转和偏离垂直， 是在取芯过程中发生的斯克里普斯的丽莎陶克斯博士 传导式全磁心直通低温磁强计 在这些核心上进行测量。拆分时，子样本将 分析了剩余磁化强度、倾斜度和衰减度 这些分析得出的数值将提供给Dr. Kleinrock将把核心头信息整合到 删除corring文物，以构建一个向下的核心历史， 每个核心的绝对旋转。他估计，至少有45个 块旋转发生在该地区，和技术 这里提出的将能够解决大约10 '的旋转。