Paleomagnetism of a Late Cretaceous island arc complex from South Sakhalin, East Asia: Convergent boundaries far away from the Asian continental margin?

2001 ◽  
Vol 106 (B9) ◽  
pp. 19193-19205 ◽  
Author(s):  
Mikhail L. Bazhenov ◽  
Alexander E. Zharov ◽  
Natalia M. Levashova ◽  
Kazuto Kodama ◽  
Nikita Y. Bragin ◽  
...  
Keyword(s):  
East Asia ◽  
Continental Margin ◽  
Late Cretaceous ◽  
Island Arc ◽  
South Sakhalin

Erosion and sedimentation in SE Tibet and Myanmar during the evolution of the Burmese continental margin from the Late Cretaceous to Early Neogene

2021 ◽  
Author(s):  
Peng Zhang ◽  
Lianfu Mei ◽  
Shao-Yong Jiang ◽  
Sihuang Xu ◽  
Raymond A. Donelick ◽  
...  
Keyword(s):  
Continental Margin ◽  
Late Cretaceous ◽  
Early Neogene ◽  
Se Tibet

Anorogenic magmatism and the Grenvillian Orogeny

1989 ◽  
Vol 26 (3) ◽  
pp. 479-489 ◽  
Author(s):  
Brian F. Windley
Keyword(s):  
United States ◽  
South America ◽  
Continental Margin ◽  
South Atlantic ◽  
Island Arc ◽  
The South ◽  
The West ◽  
Continental Block ◽  
Grenvillian Orogeny ◽  
Alkaline Complexes

The Grenvillian Orogeny was preceded by extensive anorogenic volcanism and plutonism in the period 1500–1300 Ma in the form of rhyolites, epizonal granites, anorthosites, gabbros, alkaline complexes, and basic dykes. An analogue for the mid-Proterozoic anorogenic complexes is provided by the 2000 km by 200 km belt of anorogenic complexes in the Hoggar, Niger, and Nigeria, which contain anorthosites, gabbros, and peralkaline granites and were generated in a Cambrian to Jurassic rift that farther south led to the formation of the South Atlantic. An analogue for the 1 × 106 km2 area of 1500–1350 Ma rhyolites (and associated epizonal granites) that underlie the mid-continental United States is provided by the 1.7 × 106 km2 area of Jurassic Tobifera rhyolites in Argentina, which were extruded on the stretched continental margin of South America immediately preceding the opening of the South Atlantic. The mid-Proterozoic complexes were intruded close to the continental margin of the Grenvillian ocean and were commonly superimposed by the craton-directed thrusts that characterized the final stages of the Grenvillian Orogeny. The bulk of the Keweenawan rift and associated anorogenic magmatism formed about 1100 Ma at the same time as the Ottawan Orogeny in Ontario, which probably resulted from the collision of the island arc of the Central Metasedimentary Belt attached to the continental block in the east with the continental block to the west. The most appropriate modern equivalent would be the Rhine Graben, which formed at the same time as the main Alpine compression.

scholarly journals GEODYNAMICS AND MAGMATISM OF THE PACIFIC-TYPE TRANSFORM MARGINS. ASPECTS AND DISCRIMINANT DIAGRAMS

2021 ◽  
pp. 3-24
Author(s):  
A.V. Grebennikov ◽  
◽  
A.I. Khanchuk ◽  
Keyword(s):  
Continental Margin ◽  
Tectonic Setting ◽  
Island Arc ◽  
Igneous Rocks ◽  
High Alumina ◽  
Plate Boundaries ◽  
Spreading Ridge ◽  
Convergent Margins ◽  
Oceanic Plate ◽  
Plate Movement

Transform margins represent lithospheric plate boundaries with horizontal sliding of oceanic plate, which in time and space replaced the subduction related convergent margins. This happened due to: spreading ridge–trench intersection (California; Queen Charlotte–Northern Cordilleran, West of the Antarctic Peninsula, and probably the Late Miocene–Pleistocene Southernmost South America) or ridge death along continental margin (Baja California); change in the direction of oceanic plate movement (Western Aleutian–Komandorsk; Southernmost tip of the Andes); and island arc-continent collision (New Guinea Island). Post-subduction magmatism is related to a slab window that resulted either from the spreading ridge collision (subduction) with a continental margin or slab tear formation, or slab break-off after subduction cessation due to other reasons. Igneous magmatic series formed in consequence of these events show diversity of tholeiitic (sub-alkaline), alkaline or calc-alkaline, high-alumina and adakitic rocks. The comprehensive geochemical dataset (more than 2400 analyses) on igneous rocks of the model transform and convergent geodynamic settings allowed to substantiate the most informative triple diagrams for the petrogenic oxides TiO2 × 10 – Fe2O3Tot – MgO and trace elements Nb – La– Yb. Mostly approved for the rock compositions with SiO2 < 63 wt. %, the new plots are capable of distinguishing igneous rocks formed above zones of subduction at an island arc and continental margin (related to convergent margins), from those formed in the tectonic setting of transform margins along continents or island arcs.

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.

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