DOI: 10.1016/j.epsl.2019.115945
论文题名: Subducted sediments, upper-plate deformation and dewatering at New Zealand's southern Hikurangi subduction margin
作者: Crutchley G.J. ; Klaeschen D. ; Henrys S.A. ; Pecher I.A. ; Mountjoy J.J. ; Woelz S.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2020
卷: 530 语种: 英语
中文关键词: 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
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. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/164932
Appears in Collections: 气候变化与战略
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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
Recommended Citation:
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]. Earth and Planetary Science Letters,2020-01-01,530