DOI: 10.1016/j.tecto.2021.228875
论文题名: Eocene pre- and syn-obduction tectonics in New Caledonia (Southwest Pacific), a case for oblique subduction, transcurrent tectonics and oroclinal bending; structural and paleomagnetic evidence
作者: Dominique C. ; Marion I. ; Yan C.
刊名: Tectonophysics
ISSN: 00401951
出版年: 2021
卷: 811 语种: 英语
中文关键词: fault analysis
; Oblique subduction
; oroclinal bending
; paleomagnetism
; supra-subduction dykes
; transcurrent folding
英文关键词: Kaolinite
; Metamorphic rocks
; Serpentine
; Tectonics
; Counter clockwise rotation
; Fore arc region
; Metamorphic belts
; Multi-step evolutions
; Oblique subduction
; Paleomagnetic data
; Paleomagnetic evidence
; Subduction zones
; Plates (structural components)
; dike
; Eocene
; exhumation
; folding
; foreland basin
; obduction
; oblique fault
; paleomagnetism
; subduction
; transtension
; New Caledonia [Melanesia]
英文摘要: The structural analysis of the metamorphic belt and allochthonous terranes, which represent the lower and upper plates of the Eocene subduction/obduction complex of New Caledonia respectively, unravels a multi-step evolution. At subduction inception, the originally N-S trending northern Norfolk/New Caledonia Ridge was moving northward as recorded by sheared lower Eocene dykes of the Peridotite Nappe. Fast exhumation of the fore-arc mantle in transtensional conditions was recorded by the injection of fore-arc magmas through fast-cooling peridotites, followed by the occurrence of antigorite- and tremolite-bearing crack seals in small-scale transcurrent or oblique-slip faults. Meanwhile, slices of the oceanic crust of the lower plate were scrapped off and accumulated in the fore-arc region while some elements were dragged down into the subduction zone and contributed to the formation of eclogite facies mélange. When the tip of the New Caledonia Ridge reached the trench, it progressively jammed the subduction. Meanwhile, the oblique slip and coeval rotation of the arc due to the opening of the north Loyalty back-arc basin provoked the dextral transcurrent folding of already accreted ocean crust slices and metamorphic units on the course of exhumation. Bulk counterclockwise rotation of 56° ± 5° was recorded in the foreland basin by paleomagnetic data of sediments from the 45–35 Ma time interval. The final obduction of fore-arc peridotites occurred with top-to-the-SW kinematics when the island had already reached its present orientation. © 2021 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/170796
Appears in Collections: 气候变化与战略
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作者单位: Université de la Nouvelle-Calédonie, Institut des Sciences Exactes et Appliquées (EA 7484), Avenue James Cook, Nouméa, 98850, New Caledonia; Université d'Orléans, CNRS, BRGM, ISTO, UMR 7327, Orléans, F-45071, France
Recommended Citation:
Dominique C.,Marion I.,Yan C.. Eocene pre- and syn-obduction tectonics in New Caledonia (Southwest Pacific), a case for oblique subduction, transcurrent tectonics and oroclinal bending; structural and paleomagnetic evidence[J]. Tectonophysics,2021-01-01,811