Late Cretaceous to recent plate motions in western South America revisited

Somoza, Rubén; Ghidella, Marta E.

doi:10.1016/j.epsl.2012.03.003

Cited by 146 publications

(130 citation statements)

References 88 publications

Supporting

Mentioning

125

Contrasting

Order By: Relevance

“…Although the geological record from this region is not complete enough to assess whether the main tectonic events have been synchronous across the Patagonian and Fuegian Andes, a partial time overlap of some deformational episodes within the two domains during the Cenozoic (Cande and Leslie, 1986;Thomson et al, 2011;Somoza and Ghidella, 2012;Fosdick et al, 2013) appears to be compatible with our AMS results.…”

supporting

confidence: 80%

Constraints on deformation of the Southern Andes since the Cretaceous from anisotropy of magnetic susceptibility

et al. 2015

View full text Add to dashboard Cite

supporting

confidence: 80%

Constraints on deformation of the Southern Andes since the Cretaceous from anisotropy of magnetic susceptibility

et al. 2015

View full text Add to dashboard Cite

“…2). Convergence rates between the oceanic Farallon and the South American plate are thought to have been relatively slow during the Paleocene (∼5 cm/yr), with an increase in the Mid Eocene to rates of ∼8 cm/yr (Somoza and Ghidella, 2012). This convergence rate is suggested to have remained fairly constant between the Mid Eocene and Late Oligocene, with the Farallon plate being subducted in a north-easterly (NE) direction (Pardo Casas and Molnar, 1987;Pilger, 1984;Somoza and Ghidella, 2012) (Fig.…”

Section: Geological Settingmentioning

confidence: 95%

“…2). The oceanic lithosphere being subducted during this time interval was most likely Late Cretaceous in age (Somoza and Ghidella, 2012) and subducting at a normal angle (>30 • ) (Ramos and Folguera, 2009). A significant change in the tectonic configuration of the Andean margin occurred during the Late Oligocene (∼ 25 Ma) due to the break-up of the Farallon plate into the Nazca and Cocos plates (Lonsdale, 2005).…”

Section: Geological Settingmentioning

confidence: 97%

“…Convergence rates and the relative plate motions between the oceanic (Farallon and Nazca) and South American plates have changed over time (Somoza and Ghidella, 2012) (Fig. 2).…”

Section: Geological Settingmentioning

confidence: 97%

“…This reconfiguration has been linked to a period of major uplift, increased magmatic activity, and a broadening of the magmatic arc (Pilger, 1984). The high convergence rates were sustained up until ∼ 20 Ma, and followed by a gradual decline to present day values (∼7 cm/yr) (Pilger, 1984;Somoza and Ghidella, 2012). It is suggested that progressively older, Late Cretaceous oceanic lithosphere, originating from the Farallon-Phoenix spreading ridge, was subducted along the South American margin between ∼24 and ∼16 Ma (Somoza and Ghidella, 2012).…”

Section: Geological Settingmentioning

confidence: 98%

See 2 more Smart Citations

Temporal variations in the influence of the subducting slab on Central Andean arc magmas: Evidence from boron isotope systematics

Jones

Hoog

Kirstein

et al. 2014

Earth and Planetary Science Letters

View full text Add to dashboard Cite

Editor: B. Marty Keywords: boron isotopes melt inclusions subduction zone geometry southern Central Andes slab-derived fluids Cenozoic arc magmatismThe Pampean flat-slab segment in the southern Central Andes represents an ideal setting at which to investigate how changes in the tectonic configuration of a subduction zone (convergence angles and rates, seamount subduction and shallowing slab angle) affects the recycling of subducted components to arc magmas. To constrain sources, particularly of slab-derived fluids and their contribution to arc magmatism, boron isotope and select major and trace element compositions were determined for pyroxene-and zircon-hosted melt inclusions obtained from a suite of Paleocene to Miocene arc magmatic rocks, from the southern Central Andes. Considerable changes in δ 11 B values and boron concentrations are observed with time. Significantly lower δ 11 B values (average = −1.9 ± 2.2h (1σ )) and B/Nb ratios (average = 3.3 ± 1.3 (1σ )) were obtained for melt inclusions from Oligocene arc rocks (∼ 24 Ma) compared to those from the Paleocene (∼ 61 Ma) (averages = +1.6 ± 0.8h and 17.8 ± 1.4 (1σ ), respectively) and the Miocene (∼18 Ma) (averages = +4.7 ± 1.9h and 11.9 ± 5.5 (1σ ), respectively). A slab-derived fluid with a δ 11 B composition of +1.5h, primarily derived from altered oceanic crust on the down-going slab, affected the source of the Paleocene arc magma. The source of the Oligocene arc magmas received less boron derived from the subducting slab ( 1% fluid addition) than the Paleocene and Miocene arc magmas (up to 3.5% fluid addition). This is consistent with a greater depth to the slabmantle interface and is potentially related to the widening of the volcanic arc and more distal position of these samples relative to the trench during this time period. The higher δ 11 B values (up to ∼9h) obtained for the Miocene melt inclusions record an increase in the influence of serpentinite-derived fluids on the source of arc magmas after ∼19.5 Ma. This is approximately coeval with the subduction of the Juan Fernandez Ridge (JFR), suggesting that the oceanic lithosphere associated with the subducting JFR in the Early Miocene was hydrated and serpentinised, similar to the present day ridge. As serpentinisation increases the buoyancy of the slab this finding supports the link between the intersection of the JFR with the Andean margin and the onset of flat-slab subduction.

show abstract

Paleomagnetism and magnetic fabric of the Eastern Cordillera of Colombia: Evidence for oblique convergence and nonrotational reactivation of a Mesozoic intracontinental rift

et al. 2014

View full text Add to dashboard Cite

We report the paleomagnetic and magnetic fabric results of 58 sites from Cretaceous-Miocene marine and continental strata from the Eastern Cordillera (EC) and the Cucuta zone, at the junction between the Santander Massif and the Merida Andes of Colombia. The EC is an intracontinental doubly vergent range inverting a Triassic to Early Cretaceous rift zone. Twenty-three sites reveal nonsystematic tectonic rotations, including unrotated areas of the EC range with respect to stable South America. Our data show that the EC inverted a NNE oriented rift zone and that the orientation of the Mesozoic rift and the mountain chain roughly correspond. Interestingly, magnetic lineations from anisotropy of magnetic susceptibility analysis do not trend parallel to the chain but rather are oblique to the main orogenic trend. By also considering GPS evidence of a~1 cm/yr ENE displacement of central western Colombia accommodated by the EC, we suggest that the Miocene-Recent deformation event of this belt arises from ENE oblique convergence reactivating a NNE oriented rift zone. Oblique shortening was likely partitioned into pure dip-slip shear characterizing thick-skinned frontal thrust sheets (well known along both chain fronts) and by range-parallel right-lateral strike-slip faults, which have not been identified yet, but likely exist in the axial part of the EC. Finally, the 35°± 9°clockwise rotation observed in four post-Miocene magnetically overprinted sites from the Cucuta zone reflects late Cenozoic and ongoing right-lateral strike-slip displacement occurring along faults parallel to the Boconó fault system, possibly connected with the right-lateral faults inferred to exist along the axial part of the EC.

show abstract

Late Cretaceous to recent plate motions in western South America revisited

Cited by 146 publications

References 88 publications

Constraints on deformation of the Southern Andes since the Cretaceous from anisotropy of magnetic susceptibility

Constraints on deformation of the Southern Andes since the Cretaceous from anisotropy of magnetic susceptibility

Temporal variations in the influence of the subducting slab on Central Andean arc magmas: Evidence from boron isotope systematics

Paleomagnetism and magnetic fabric of the Eastern Cordillera of Colombia: Evidence for oblique convergence and nonrotational reactivation of a Mesozoic intracontinental rift

Contact Info

Product

Resources

About