Tectonic evolution of the Cocos-Nazca spreading center

Hey, R. N.

doi:10.1130/0016-7606(1977)88<1404:teotcs>2.0.co;2

Cited by 334 publications

(175 citation statements)

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“…First, areas characterized by very narrow subducted oceanic slabs like the Scotia Sea ( Figure B2) are difficult to interpret with our model but can be explained by faster slab rollback due to the decreased viscous resistance in the mantle to the narrower slab [Schellart et al, 2007]. Second, our model is difficult to apply to areas where the indentor is very wide or has smaller buoyancy contrasts with adjacent, late Cenozoic oceanic crust like the Ontong Java Plateau (width of indentor is $1000 km, Figure B3) or the Cocos Ridge (ridge is Miocene in age, flanking Miocene oceanic crust [Hey, 1977;Sdrolias and Mueller, 2006]). For very broad and thick indentors like the Ontong Java Plateau, its great width and crustal thickness causes initiation of new back-arc thrust zones by subduction polarity reversal to accommodate the collision and indentation of the arc and trench; the initiation of new subduction in a back-arc area would inhibit collision-induced rotation of the fore arc.…”

Section: Discussionmentioning

confidence: 99%

Collisional model for rapid fore‐arc block rotations, arc curvature, and episodic back‐arc rifting in subduction settings

Wallace

Ellis

Mann

2009

Geochem Geophys Geosyst

104

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[1] We review geophysical and geological data from 23 active and ancient plate boundaries to document a compelling spatial and temporal relationship between collision, plate boundary curvature, rapid tectonic rotations, and the occurrence of back-arc rifting. Our observations support a conceptual model where the change from subduction to collision causes rapid fore-arc rotation (when viewed in a reference frame relative to the bounding tectonic plates), leading to marked plate boundary curvature. Our global compilation reveals that most active back-arc rifts are associated with rapidly rotating fore arcs and nearby collisions. Thus, we propose that collision and rapid fore-arc rotations play a major role in the evolution and kinematics of back-arc basins. We conduct numerical modeling to better understand the physical processes behind these observed rapid tectonic rotations at convergent margins. Our results suggest that the presence of an indentor or choke point in the subduction system (e.g., collision) can generate rapid rotation of the fore arc about a nearby pole and lead to back-arc rifting. The rate of fore-arc rotation and back-arc rifting depends on the incoming indentor velocity and can be greatly enhanced by slab rollback and the presence of a low-viscosity back arc. Where viscosity of the back arc is low, fore-arc rotation dominates; where back-arc viscosity is high, the formation of strike-slip faults and tectonic escape dominates. Our observational and model-derived results illustrate that shallow crustal forces produced by the entry of buoyant features into subduction zones are a fundamental mechanism for the generation of fore-arc block rotations, plate boundary curvature, back-arc rift evolution, and tectonic escape in subduction systems. Rollback of the subducting slab within the mantle will certainly enhance the processes we describe but it is not the only driving force. Wallace, L. M., S. Ellis, and P. Mann (2009), Collisional model for rapid fore-arc block rotations, arc curvature, and episodic back-arc rifting in subduction settings, Geochem. Geophys. Geosyst., 10, Q05001,

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Section: Discussionmentioning

confidence: 99%

Collisional model for rapid fore‐arc block rotations, arc curvature, and episodic back‐arc rifting in subduction settings

Wallace

Ellis

Mann

2009

Geochem Geophys Geosyst

104

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“…The Malpelo ridge has been suggested to be the older part of the Cocos ridge (Hey 1977;Lonsdale and Klitgord 1978;Meschede et al 1998). The paleogeographic restoration at 15 Ma (Fig.…”

Section: Paleogeographic Restorationsmentioning

confidence: 99%

“…A paleogeographic restoration juxtaposes the smaller Malpelo ridge, presently located east of the Panama Fracture zone on the Nacza plate ( Fig. 1), in prolongation of the Cocos ridge (Hey 1977;Lonsdale and Klitgord 1978;Meschede et al 1998). A missing part of approximately 250 km of the once continuous Cocos-Malpelo ridge system has already been subducted beneath the Central American landbridge.…”

Section: Introductionmentioning

confidence: 99%

“…The Cocos, Malpelo, and Carnegie ridges have been interpreted to be hotspot traces which began to form when the Galµpagos hotspot initiated at approximately 20±22 Ma (Hey 1977;Lonsdale and Klitgord 1978). Meschede et al (1998) have demonstrated that the products of the hotspot volcanism overprinted a complex pattern of oceanic crust formed at three subsequently active, symmetric spreading systems of different orientation, which is in contrast to older reconstructions (e.g., Hey 1977;Lonsdale and Klitgord 1978).…”

Section: Introductionmentioning

confidence: 99%

“…Meschede et al (1998) have demonstrated that the products of the hotspot volcanism overprinted a complex pattern of oceanic crust formed at three subsequently active, symmetric spreading systems of different orientation, which is in contrast to older reconstructions (e.g., Hey 1977;Lonsdale and Klitgord 1978). The identified extinct spreading systems represent precursors of the presently active Cocos-Nazca spreading center (Fig.…”

Section: Introductionmentioning

confidence: 99%

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The relationship of the Cocos and Carnegie ridges: age constraints from paleogeographic reconstructions

Meschede

Barckhausen

2001

Int J Earth Sci

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Segmentation and eruptive activity along the East Pacific Rise at 16°N, in relation with the nearby Mathematician hotspot

Saout

Deschamps

Soule

et al. 2014

Geochem Geophys Geosyst

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The 16 N segment of the East Pacific Rise is the most overinflated and shallowest of this fastspreading ridge, in relation with an important magma flux due to the proximity of the Mathematician hotspot. Here, we analyze the detailed morphology of the axial dome and of the Axial Summit Trough (AST), the lava morphology, and the geometry of fissures and faults, in regard to the attributes of the magma chamber beneath and of the nearby hotspot. The data used are 1 m resolution bathymetry combined with seafloor photos and videos. At the dome summit, the AST is highly segmented by 10 third-order and fourth-order discontinuities over a distance of 30 km. Often, two contiguous and synchronous ASTs coexist. Such a configuration implies a wide (1100 m minimum) zone of diking. The existence of contiguous ASTs, their mobility, their general en echelon arrangement accommodating the bow shape of the axial dome toward the hotspot, plus the existence of a second magma lens under the western half of the summit plateau, clearly reflect the influence of the hotspot on the organization of the spreading system. The different ASTs exhibit contrasted widths and depths. We suggest that narrow ASTs reflect an intense volcanic activity that produces eruptions covering the tectonic features and partially filling the ASTs. AST widening and deepening would indicate a decrease in volcanic activity but with continued dike intrusions at the origin of abundant sets of fissures and faults that are not masked by volcanic deposits.

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Tectonic evolution of the Cocos-Nazca spreading center

Cited by 334 publications

References 0 publications

Collisional model for rapid fore‐arc block rotations, arc curvature, and episodic back‐arc rifting in subduction settings

Collisional model for rapid fore‐arc block rotations, arc curvature, and episodic back‐arc rifting in subduction settings

The relationship of the Cocos and Carnegie ridges: age constraints from paleogeographic reconstructions

Segmentation and eruptive activity along the East Pacific Rise at 16°N, in relation with the nearby Mathematician hotspot

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