Rb–Sr and Sm–Nd isotopic systematics of the Hayachine–Miyamori ophiolitic complex: Melt generation process in the mantle wedge beneath an Ordovician island arc

2007 ◽  
Vol 11 (1-2) ◽  
pp. 234-246 ◽  
Author(s):  
Masako Yoshikawa ◽  
Kazuhito Ozawa
Keyword(s):  
Mantle Wedge ◽  
Island Arc ◽  
Generation Process ◽  
Melt Generation ◽  
Ophiolitic Complex

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.

Recycling in the Puerto Rican mantle wedge, Greater Antilles Island Arc

Island Arc ◽  
2002 ◽  
Vol 11 (1) ◽  
pp. 10-24 ◽  
Author(s):  
WAYNE T. JOLLY ◽  
EDWARD G. LIDIAK ◽  
ALAN P. DICKIN ◽  
TSAI-WAY WU
Keyword(s):  
Puerto Rican ◽  
Mantle Wedge ◽  
Island Arc ◽  
Greater Antilles

scholarly journals Cr - spinel and clinopyroxene compositions from metagabbro of Nui Ngoc complex in Tam Ky area: evidence of island - arc magma

2021 ◽  
Vol 62 (5) ◽  
pp. 1-11
Author(s):  
Thanh Xuan Ngo ◽  
Du Khac Nguyen ◽  
Dao Anh Vu . ◽  
Chi Thi Pham ◽  
Hanh Hong Thi Nguyen ◽  
...  
Keyword(s):  
Suture Zone ◽  
Island Arc ◽  
Research Results ◽  
Continental Arc ◽  
Study Results ◽  
Ophiolitic Complex ◽  
Arc Magma

The hornblende and biotite - bearing metagabbro of the Nui Ngoc complex were exposed into a few small blocks in the southwest Tam Ky city and were viewed as parts of the Tam Ky - Phuoc Son ophiolitic complex (TPO). These rocks were undergone mylonitic deformation and metamorphism. The rocks consist mainly of orthopyroxene, clinopyroxene, plagioclase, olivine, hornblende, biotite and very few microscopic Cr - spinel. The clinopyroxene and Cr - spinel minerals were analyzed for their composition by EPMA, the results showed that: (1) The clinopyroxenes have low Al2O3 (3,2÷3,5 wt %), TiO2 (0,70÷0,82 wt %) contents and (2) the Cr - spinels have low TiO2 (0,23÷0,58 wt %) content and Mg#100* (Mg/ (Mg+Fe2+)) (32÷42) but has medium Cr# (Cr/ (Cr+Al)) (45÷52).These features are similar to those of rocks formed in anoceanic - oceanicsubduction zone that was reported for the plagiogranite of Dieng Bong complex nearby. This study results combined with previous research results in the Tam Ky - Phuoc Son suture zone show the existence of island arc, continental arc, and MOR - magmatic types.

scholarly journals Refining material transport in the mantle wedge of the northernmost Tonga island arc

2021 ◽  
Author(s):  
Bettina Storch ◽  
Marcel Regelous ◽  
Kristina Noebel ◽  
Karsten Haase ◽  
Julia Bauer
Keyword(s):  
Mantle Wedge ◽  
Island Arc ◽  
Material Transport
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