The Geometry of the Continental Wedge and Its Relation to the Rheology and Seismicity of the Chilean Interplate Boundary

Maksymowicz, Andrei; Tassara, Andrés Ollero

doi:10.1007/978-3-319-67774-3_2

Cited by 2 publications

(4 citation statements)

References 83 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The northern Chilean convergent margin is characterized by the subduction of the oceanic Nazca plate beneath the continental South American plate (Figure 1) at a currently convergence rate of ~67 mm/a (Khazaradze & Klotz, 2003), although the average convergence rate during the last 20 Ma is about 85 mm/a (DeMets et al 2010). The Nazca plate in the study region (18º -21ºS) was formed in the East Pacific Rise 45-52 Ma (Mueller et al, 2008), whereas its crustal thickness is 6-7 km thick inferred by seismic constraints (Patzwahl et al, 1999;Ranero and Sallarès, 2004;Contreras-Reyes et al, 2012;Maksymowicz et al, 2018). The northern Chilean margin has a poorly sedimented trench (< 200 m; Maksymowicz et al, 2018) due to the reduced sediment supply from the Andes in the extremely arid region of the Atacama Desert.…”

mentioning

confidence: 90%

“…The Nazca plate in the study region (18º -21ºS) was formed in the East Pacific Rise 45-52 Ma (Mueller et al, 2008), whereas its crustal thickness is 6-7 km thick inferred by seismic constraints (Patzwahl et al, 1999;Ranero and Sallarès, 2004;Contreras-Reyes et al, 2012;Maksymowicz et al, 2018). The northern Chilean margin has a poorly sedimented trench (< 200 m; Maksymowicz et al, 2018) due to the reduced sediment supply from the Andes in the extremely arid region of the Atacama Desert. The continental slope is steep as the frontal part of the margin lacks a well-developed frontal prism (Contreras-Reyes 2018; Maksymowicz et al, 2018).…”

mentioning

confidence: 94%

“…The northern Chilean margin has a poorly sedimented trench (< 200 m; Maksymowicz et al, 2018) due to the reduced sediment supply from the Andes in the extremely arid region of the Atacama Desert. The continental slope is steep as the frontal part of the margin lacks a well-developed frontal prism (Contreras-Reyes 2018; Maksymowicz et al, 2018).…”

mentioning

confidence: 99%

See 2 more Smart Citations

Northern Chile intermediate-depth earthquakes controlled by plate hydration

Cabrera

Ruiz

Poli

et al. 2020

Geophysical Journal International

View full text Add to dashboard Cite

Summary We investigate the variations of the seismic source properties and aftershock activity using kinematic inversions and template-matching, for six large magnitude intermediate-depth earthquakes occurred in northern Chile. Results show similar rupture geometry and stress drop values between 7–30 MPa. Conversely, aftershocks productivity systematically decreases for the deeper events within the slab. Particularly there is a dramatic decrease in aftershock activity below the 400–450°C isotherm-depth, which separates high and low-hydrated zones. The events exhibit tensional focal mechanisms at unexpected depths within the slab, suggesting a deepening of the neutral plane, where the extensional regimen reaches the 700–800°C isotherm-depth. We interpret the reduction of aftershocks in the lower part of the extensional regime as the absence of a hydrated-slab at those depths. Our finding highlights the role of the thermal-structure and fluids in the subducting plate, in controlling the intermediated-depth seismic activity and shed new light in their causative mechanism.

show abstract

mentioning

confidence: 90%

mentioning

confidence: 94%

See 1 more Smart Citation

Northern Chile intermediate-depth earthquakes controlled by plate hydration

Cabrera

Ruiz

Poli

et al. 2020

Geophysical Journal International

View full text Add to dashboard Cite

show abstract

“…Although a high degree of interplate coupling can also characterize steep subduction (depending on convergence rate), this is gener-ally less effective with respect to that associated with shallow to flat-slab segments (Gutscher, 2002). At present, slab dip varies significantly along the Andean margin from the dominant dip angle of ∼30° to flat-slab segments (Ramos and Folguera, 2009;Maksymowicz and Tassara, 2018). This results in along-strike segmentation and coupling variations that influence magmatism and the style of recent to active deformation of the overriding plate (Coira et al, 1993;Yáñez and Cembrano, 2004;Ramos and Folguera, 2009).…”

Section: Introductionmentioning

confidence: 98%

The role of slab geometry in the exhumation of cordilleran-type orogens and their forelands: Insights from northern Patagonia

et al. 2021

View full text Add to dashboard Cite

In cordilleran-type orogens, subduction geometry exerts a fundamental control on the tectonic behavior of the overriding plate. An integrated low-temperature, large thermochronological data set is used in this study to investigate the burial and exhumation history of the overriding plate in northern Patagonia (40°−45°S). Thermal inverse modeling allowed us to establish that a ∼2.5−4-km-thick section originally overlaid the Jurassic−Lower Cretaceous successions deposited in half-graben systems that are presently exposed in the foreland. Removal of the sedimentary cover started in the late Early Cretaceous. This was coeval with an increase of the convergence rate and a switch to a westward absolute motion of the South American Plate that was accompanied by shallowing of the subducting slab. Unroofing was probably further enhanced by Late Cretaceous to early Paleogene opening of a slab window beneath the overriding plate. Following a tectonically quiescent period, renewed exhumation occurred in the orogen during relatively fast Neogene plate convergence. However, even the highly sensitive apatite (U-Th)/He thermochronometer does not record any coeval cooling in the foreland. The comparison between Late Cretaceous and Neogene exhumation patterns provides clear evidence of the fundamental role played by inter-plate coupling associated with shallow slab configurations in controlling plate-scale deformation. Our results, besides highlighting for the first time how the whole northern Patagonia foreland was affected by an exhumation of several kilometers since the Late Cretaceous, provide unrivalled evidence of the link between deep geodynamic processes affecting the slab and the modes and timing of unroofing of different sectors of the overriding plate.

show abstract

The Geometry of the Continental Wedge and Its Relation to the Rheology and Seismicity of the Chilean Interplate Boundary

Cited by 2 publications

References 83 publications

Northern Chile intermediate-depth earthquakes controlled by plate hydration

Northern Chile intermediate-depth earthquakes controlled by plate hydration

The role of slab geometry in the exhumation of cordilleran-type orogens and their forelands: Insights from northern Patagonia

Contact Info

Product

Resources

About