沃顿盆地板内变形带共轭断裂系的发现。

The discovery of a conjugate system of faults in the Wharton Basin intraplate deformation zone.

机构信息

Equipe de Géosciences Marines, Institut de Physique du Globe de Paris (CNRS, Paris Diderot, Sorbonne Paris Cité), 1 rue Jussieu, 75238 Paris Cedex 05, France.; Earth Observatory of Singapore, Nanyang Technological University, N2-01A-XX, 50 Nanyang Avenue, Singapore 639798, Singapore.

Research Center for Geotechnology, Indonesian Institute of Sciences, Komplek LIPI Jl., Sangkuriang Bandung 40135, Indonesia.

出版信息

Sci Adv. 2017 Jan 4;3(1):e1601689. doi: 10.1126/sciadv.1601689. eCollection 2017 Jan.

DOI:10.1126/sciadv.1601689

PMID:28070561

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC5214956/

Abstract

The deformation at well-defined, narrow plate boundaries depends on the relative plate motion, but how the deformation takes place within a distributed plate boundary zone remains a conundrum. This was confirmed by the seismological analyses of the 2012 great Wharton Basin earthquakes [moment magnitude () 8.6], which suggested the rupture of several faults at high angles to one another. Using high-resolution bathymetry and seismic reflection data, we report the discovery of new N294°E-striking shear zones, oblique to the plate fabric. These shear zones are expressed by sets of normal faults striking at N335°E, defining the direction of the principal compressional stress in the region. Also, we have imaged left-lateral strike-slip faults along reactivated N7°E-oriented oceanic fracture zones. The shear zones and the reactivated fracture zones form a conjugate system of faults, which accommodate present-day intraplate deformation in the Wharton Basin.

摘要

在明确的狭窄板块边界处的变形取决于相对板块运动，但变形如何在分布式板块边界区域内发生仍然是一个难题。2012 年沃顿海盆大地震的地震学分析证实了这一点[矩震级（）8.6]，该分析表明多个断层以高角度相互破裂。利用高分辨率水深测量和地震反射数据，我们报告了新的 N294°E 走向剪切带的发现，这些剪切带与板块构造斜交。这些剪切带由一组走向 N335°E 的正断层组成，确定了该区域主压应力的方向。此外，我们还对沿重新激活的 N7°E 走向的大洋断裂带的左旋走滑断层进行了成像。剪切带和重新激活的断裂带形成了一组共轭断层，这些断层可适应沃顿海盆现今的板块内变形。