Links among mountain building, surface erosion, and growth of an accretionary prism in a subduction zone—An example from southwest Japan

2008 ◽  
pp. 391-403 ◽  
Author(s):  
Gaku Kimura ◽  
Yujin Kitamura ◽  
Asuka Yamaguchi ◽  
Hugues Raimbourg
Keyword(s):  
Subduction Zone ◽  
Accretionary Prism ◽  
Surface Erosion ◽  
Southwest Japan ◽  
Mountain Building

scholarly journals Interseismic deformation of the Nankai subduction zone, southwest Japan, inferred from three-dimensional crustal velocity fields

2007 ◽  
Vol 59 (10) ◽  
pp. 1073-1082 ◽  
Author(s):  
Takao Tabei ◽  
Mari Adachi ◽  
Shin’ichi Miyazaki ◽  
Tsuyoshi Watanabe ◽  
Sayomasa Kato
Keyword(s):  
Subduction Zone ◽  
Three Dimensional ◽  
Velocity Fields ◽  
Southwest Japan ◽  
Crustal Velocity ◽  
Interseismic Deformation ◽  
Nankai Subduction Zone

scholarly journals The Imbert Formation of northern Hispaniola: a tectono-sedimentary record of arc-continent collision and ophiolite emplacement in the northern Caribbean subduction-accretionary prism

2015 ◽  
Vol 7 (2) ◽  
pp. 1827-1876 ◽  
Author(s):  
J. Escuder-Viruete ◽  
A. Suárez-Rodríguez ◽  
J. Gabites ◽  
A. Pérez-Estaún
Keyword(s):  
Subduction Zone ◽  
Continental Margin ◽  
Middle Eocene ◽  
Accretionary Prism ◽  
Island Arc ◽  
Caribbean Island ◽  
Stratigraphic Sequence ◽  
Oblique Collision ◽  
The Caribbean ◽  
Ophiolitic Complex

Abstract. In northern Hispaniola, the Imbert Formation (Fm) has been interpreted as an orogenic "mélange" originally deposited as trench-fill sediments, an accretionary (subduction) complex formed above a SW-dipping subduction zone, or the sedimentary result of the early oblique collision of the Caribbean plate with the Bahama Platform in the middle Eocene. However, new stratigraphical, structural, geochemical and geochronological data from northern Hispaniola indicate that the Imbert Fm constitutes a coarsening-upward stratigraphic sequence that records the transition of the sedimentation from a pre-collisional forearc to a syn-collisional piggy-back basin. This piggy-back basin was transported on top of the Puerto Plata ophiolitic complex slab and structurally underlying accreted units of the Rio San Juan complex, as it was emplaced onto the North America continental margin units. The Imbert Fm unconformably overlies different structural levels of the Caribbean subduction-accretionary prism, including a supra-subduction zone ophiolite, and consists of three laterally discontinuous units that record the exhumation of the underlying basement. The distal turbiditic lower unit includes the latest volcanic activity of the Caribbean island arc; the more proximal turbiditic intermediate unit is moderately affected by syn-sedimentary faulting; and the upper unit is a (caotic) olistostromic unit, composed of serpentinite-rich polymictic breccias, conglomerates and sandstones, strongly deformed by syn-sedimentary faulting, slumping and sliding processes. The Imbert Fm is followed by subsidence and turbiditic deposition of the overlying El Mamey Group. The 40Ar / 39Ar plagioclase plateau ages obtained in gabbroic rocks from the Puerto Plata ophiolitic complex indicate its exhumation at ∼ 45–40 Ma (lower-to-middle Eocene), contemporaneously to the sedimentation of the overlying Imbert Fm. These cooling ages imply the uplift to the surface and submarine erosion of the complex to be the source of the ophiolitic fragments in the Imbert Fm, during of shortly after the emplacement of the intra-oceanic Caribbean island-arc onto the continental margin.

Timing of subduction zone metamorphism during the formation and emplacement of Troodos and Baer–Bassit ophiolites: insights from 40Ar–39Ar geochronology

2007 ◽  
Vol 144 (5) ◽  
pp. 797-810 ◽  
Author(s):  
GAVIN HEUNG-NGAI CHAN ◽  
JOHN MALPAS ◽  
COSTAS XENOPHONTOS ◽  
CHING-HUA LO
Keyword(s):  
Subduction Zone ◽  
Late Cretaceous ◽  
Accretionary Prism ◽  
Passive Margin ◽  
Metamorphic Rocks ◽  
Metamorphic Complex ◽  
Troodos Ophiolite ◽  
Crustal Thinning ◽  
Step Heating ◽  
Short Time

The Troodos ophiolite in Cyprus and Baer–Bassit ophiolite in Syria together form part of the Tethyan ophiolite belt. They were generated in a supra-subduction zone setting in Late Cretaceous times. As with many of the ophiolite occurrences in this belt, the sequences are closely associated with tectonic ‘coloured mélange’ zones, which contain, among a variety of lithologies, metre- to kilometre-size blocks of metamorphic rocks. Precise 40Ar–39Ar laser step-heating experiments performed on four amphibolites from SW Cyprus and six from NW Syria, yield plateau ages ranging from 75.7±0.3 Ma to 88.9±0.8 Ma in Cyprus and 71.7±0.5 to 88.4±0.4 Ma in Syria. The older limits of these time spans are coeval with the age of the formation of the associated ophiolites. Unlike other metamorphic sole rocks which seem to form in relatively short time spans, these metamorphic rocks found in Cyprus and Syria are interpreted to have formed in Late Cretaceous times by accretion below the overriding Troodos and Baer–Bassit crust for a period of 15–18 Ma. The metamorphic complexes were exhumed by extension and crustal thinning associated with subduction roll-back and the rotation of the overriding plate until the cessation of subduction in Maastrichtian times. In Cyprus, the exhumed metamorphic complex was incorporated into an accretionary prism constructed primarily of the collapsed Mamonia passive margin sequence intercalated with rocks of the Troodos ophiolite during plate collision in the Maastrichtian. Concomitantly, in Syria, the Baer–Bassit ophiolite and subcreted metamorphic complex were emplaced onto the Arabian passive margin and fragmented into blocks and knockers, forming the Baer–Bassit mélange.

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