Neogene tectonic stress fields of northeast Honshu Arc and implications for plate boundary conditions
Neogene tectonic stress fields of northeast Honshu Arc and implications for plate boundary conditions
复制标题
本州弧东北部新近纪构造应力场及其对板块边界条件的影响
DOI：
10.1016/0040-1951(90)90014-y
复制
发表时间：
1990
期刊：
影响因子：
2.9
通讯作者：
K. Otsuki
中科院分区：
文献类型：
--
作者：
K. Otsuki
对 3300 多个含金属矿脉进行了分析，利用基本断裂力学重建了本州岛弧东北部的新近纪构造应力场。矿脉分为主导的 NE 系统和从属的 E-W、N-S 和 NW 系统。 NE系统与共轭走滑断层和伸展节理或正断层组合有关，形成时间为15至5 Ma。裂缝表明σ1 或σ2 取向为ENE，σ3 取向为NNW。σ3 被认为是张性的，因为没有脉体与逆冲断层相关。该应力方向既不垂直也不平行于日本海沟的轴线，太平洋板块在日本海沟向西北偏西方向移动并俯冲到东北本州岛弧之下。应力方向和板块运动学之间的不一致可以通过与本州弧东北部周围的其他板块边界相关的动力效应来解释，即北海道轴性带和糸鱼川-静冈构造线上的挤压。此外，日本海沟、伊豆-本宁海沟和相模海槽的三重交界处可能位于距现在位置东北300-400公里处，南海海槽-相模海槽的俯冲带被认为是张性板块边界。重建的应力场与15 Ma左右的拉张弧后裂谷一致。
More than 3300 metalliferous veins were analyzed to reconstruct the Neogene tectonic stress field of the northeast Honshu Arc using basic fracture mechanics. The veins are grouped into a dominant NE system and subordinate E-W, N-S and NW systems. The NE system is associated with assemblages of conjugate strike-slip faults and extension joints or normal faults which were formed during a period from 15 to 5 Ma. The fractures suggest thatσ1orσ2was oriented ENE andσ3was oriented NNW.σ3is thought to have been tensional, because no veins are associated with thrust faults. This stress orientation is neither perpendicular nor parallel to the axis of the Japan Trench where the Pacific plate was moving west-northwest and was subducted under the northeast Honshu Arc. The inconsistency between the stress orientation and the plate kinematics can be explained by the dynamic effects related to other plate boundaries surrounding the northeast Honshu Arc, namely compression on the Hokkaido Axial Zone and the Itoigawa-Shizuoka Tectonic Line. In addition, the triple junction of the Japan Trench, Izu-Bonnin Trench and the Sagami Trough was probably located 300–400 km northeast from its present position and the subduction zone of Nankai Trough-Sagami Trough is assumed to have been a tensional plate boundary. The reconstructed stress field is consistent with transtensional backarc rifting at about 15 Ma.