气候变化领域集成服务门户(CCPortal): Subducted sediments, upper-plate deformation and dewatering at New Zealand's southern Hikurangi subduction margin

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DOI	10.1016/j.epsl.2019.115945
	Subducted sediments, upper-plate deformation and dewatering at New Zealand's southern Hikurangi subduction margin
	Crutchley G.J.; Klaeschen D.; Henrys S.A.; Pecher I.A.; Mountjoy J.J.; Woelz S.
发表日期	2020
ISSN	0012821X
卷号	530
英文摘要	The southern end of New Zealand's Hikurangi subduction margin accommodates highly oblique convergence between the Pacific and Australian plates. We carry out two-dimensional (2D) seismic reflection tomography and pre-stack depth migrations on two seismic lines to gain insight into the nature of subducted sediments and upper plate faulting and dewatering at the toe of the wedge. We also investigate the NE to SW evolution of emergent upper plate thrust faulting using 47 seismic lines spanning an along-strike distance of ∼270 km. The upper sequence of sediments that ultimately gets subducted (the MES sequence) has an anomalously-low seismic velocity character. At the southwestern end of the margin, ∼150 km east of Kaikōura, the MES sequence has experienced greater compaction (for an equivalent effective vertical stress) than it has some 200 km further to the northeast. This difference is likely attributable to greater horizontal compression in the southwest caused by impingement of the Chatham Rise on the deformation front. Relationships between velocity and effective vertical stress suggest that the MES sequence is well-drained in the vicinity of frontal thrusts, corroborated by evidence for upper plate dewatering along those thrusts. Effective drainage of the MES sequence likely promotes interplate coupling on the southern Hikurangi margin. The décollement is generally hosted near a seismic reflector known as “Reflector 7”. East of Kaikōura, however, Reflector 7 becomes accreted, indicating that subduction slip at the southwestern end of the margin is no longer hosted at (or above) this reflector. Instead, the décollement steps down to a deeper stratigraphic level further inboard. Further to the SW, approximately in line with the lower Kaikōura Canyon, the offshore manifestation of subduction-driven compression ceases. © 2019 Elsevier B.V.
关键词	dewatering Hikurangi subduction margin pre-stack depth migration reflection tomography subducted sediments subduction to strike slip transition
英文关键词	Deformation; Faulting; Offshore oil well production; Reflection; Sediments; Seismic waves; Seismology; Stratigraphy; Tomography; Hikurangi subduction margins; Interplate coupling; Pre-stack depth migrations; Seismic reflections; Seismic reflectors; Seismic velocities; subduction to strike slip transition; Two Dimensional (2 D); Dewatering; deformation; dewatering; faulting; marine sediment; plate convergence; prestack migration; seismic reflection; seismic tomography; strike-slip fault; subduction zone; Hikurangi Margin; Kaikoura Canyon; Pacific Ocean
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/202554
作者单位	GNS Science, 1 Fairway Drive, Lower Hutt, 5011, New Zealand; GEOMAR Helmholtz Centre for Ocean Research Kiel, Wischhofstr. 1-3, Kiel, 24148, Germany; University of Auckland, 23 Symonds Street, Auckland, 1142, New Zealand; National Institute of Water and Atmospheric Research (NIWA), 301 Evans Bay Parade, Wellington, 6021, New Zealand
推荐引用方式 GB/T 7714	Crutchley G.J.,Klaeschen D.,Henrys S.A.,et al. Subducted sediments, upper-plate deformation and dewatering at New Zealand's southern Hikurangi subduction margin[J],2020,530.
APA	Crutchley G.J.,Klaeschen D.,Henrys S.A.,Pecher I.A.,Mountjoy J.J.,&Woelz S..(2020).Subducted sediments, upper-plate deformation and dewatering at New Zealand's southern Hikurangi subduction margin.Earth and Planetary Science Letters,530.
MLA	Crutchley G.J.,et al."Subducted sediments, upper-plate deformation and dewatering at New Zealand's southern Hikurangi subduction margin".Earth and Planetary Science Letters 530(2020).