Full Waveform Inversion Beneath the Central Andes: Insight Into the Dehydration of the Nazca Slab and Delamination of the Back‐Arc Lithosphere

Gao, Yajian; Tilmann, Frederik; Herwaarden, Dirk-Philip van; Thrastarson, Sölvi; Fichtner, Andreas; Heit, B.; Yuan, Xiaohui; Schurr, Bernd

doi:10.1029/2021jb021984

Cited by 29 publications

(41 citation statements)

References 159 publications

(474 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Accordingly, pure-shear deformation at 33°S would be mainly related to a more felsic and weaker crust; in contrast, simple-shear deformation at 36°S would result from a mafic and stronger crust . These results are compatible with gravity-constrained density distributions in the crust in the same region as proposed by Rodriguez Piceda et al (2021) and with our results of a N-S-oriented decrease in crustal temperatures. Furthermore, our results provide insights into the controversial debate over the governing mechanisms responsible for the formation of the spatially disparate thick-skinned deformation in the broken-foreland provinces of the Sierras Pampeanas between 27° and 33°S and the Santa Bárbara System farther north.…”

Section: Implications Of the Thermal Field For The Deformation Modes ...supporting

confidence: 94%

“…These layers comprise, from top to bottom: (1) water; (2) marine sediments; (3) continental sediments; (4) upper continental crystalline crust; (5) lower continental crystalline crust; (6) continental lithospheric mantle; (7) shallow oceanic crust; (8) deep oceanic crust; (9) oceanic lithospheric mantle; and (10) oceanic sub-lithospheric mantle. Figure 2 illustrates the main structural features of the 3D model (see Rodriguez Piceda et al (2021) for more details) Overall, maximum sedimentary thickness occurs in the Cuyo and Neuquén basins (Fig. 2a).…”

Section: Lithospheric Configuration Of the Southern Central Andesmentioning

confidence: 99%

“…To better illustrate this relationship, we obtained the overall 3D thermal field by combining the calculated steady-state conductive thermal field above the lower boundary condition (50-km approximation) with the temperatures deduced from seismic tomography between 50 and 200 km bmsl. From this combined model, the temperatures corresponding to the depth of the subduction interface as presented by Rodriguez Piceda et al (2021) and the volumetric extent of the low-temperature CN and FS mantle domains were extracted (Fig. 12).…”

Section: Controlling Factors Of the Lithospheric Thermal Fieldmentioning

confidence: 99%

“…It is likely that the resolution of the S wave tomography could have influenced the results within the latter area. North of the flat slab, highresolution tomography Gao et al, 2021) identifies a N-S increase of vs at 27°S with a sharp transition between low vs in the southern Andean Plateau (also known as the southern Puna Plateau) and high vs in the Sierras Pampeanas. Low vs in the southern Puna is mainly associated with the delamination of the lower crust and the mantle .…”

Section: Controlling Factors Of the Lithospheric Thermal Fieldmentioning

confidence: 99%

“…The 3D thermal model presented in this publication is accessible at Rodriguez Piceda et al (2021) via GFZ Data Services.…”

Section: Open Researchmentioning

confidence: 99%

See 4 more Smart Citations

Controls of the lithospheric thermal field of an ocean-continent subduction zone: the southern Central Andes

Piceda¹,

Scheck‐Wenderoth²,

Sippel³

et al. 2021

Preprint

View full text Add to dashboard Cite

In an ocean-continent subduction zone, the assessment of the lithospheric thermal state is essential to determine the controls of the deformation within the upper plate and the dip angle of the subducting lithosphere. In this study, we evaluate the degree of influence of both the configuration of the upper plate and variations of the subduction angle on the lithospheric thermal field of the southern Central Andes (29°–39°S). Here, the subduction angle increases from subhorizontal (5°) north of 33°S, to steep (~30°) in the south. We derived the 3D temperature and heat flow distribution of the lithosphere in the southern Central Andes considering conversion of S wave tomography to temperatures together with steady-state conductive modeling. We found that the orogen is overall warmer than the forearc and the foreland, and that the lithosphere of the northern part of the foreland appears colder than its southern counterpart. Sedimentary blanketing and the thickness of the radiogenic crust exert the main control on the shallow thermal field (< 50 km depth). Specific conditions are present where the oceanic slab is relatively shallow (< 85 km depth) and the radiogenic crust is thin, This configuration results in relatively colder temperatures compared to regions where the radiogenic crust is thick and the slab is steep. At depths >50 km, the temperatures of the overriding plate are mainly controlled by the mantle heat input and the subduction angle. The thermal field of the upper plate likely preserves the flat subduction angle and influences the spatial distribution of shortening.

show abstract

Section: Implications Of the Thermal Field For The Deformation Modes ...supporting

confidence: 94%

Section: Lithospheric Configuration Of the Southern Central Andesmentioning

confidence: 99%

Section: Controlling Factors Of the Lithospheric Thermal Fieldmentioning

confidence: 99%

Section: Controlling Factors Of the Lithospheric Thermal Fieldmentioning

confidence: 99%

“…The 3D thermal model presented in this publication is accessible at Rodriguez Piceda et al (2021) via GFZ Data Services.…”

Section: Open Researchmentioning

confidence: 99%

See 3 more Smart Citations

Controls of the lithospheric thermal field of an ocean-continent subduction zone: the southern Central Andes

Piceda¹,

Scheck‐Wenderoth²,

Sippel³

et al. 2021

Preprint

View full text Add to dashboard Cite

show abstract

SASSY21: A 3-D seismic structural model of the lithosphere and underlying mantle beneath Southeast Asia from multi-scale adjoint waveform tomography

Wehner

Blom

Rawlinson

et al. 2021

Preprint

View full text Add to dashboard Cite

We present the first continental-scale seismic model of the lithosphere and underlying mantle beneath Southeast Asia obtained from adjoint waveform tomography (often referred to as full-waveform inversion or FWI), using seismic data filtered at periods from 20 to 150 s. Based on >3,000 hr of analyzed waveform data gathered from ∼13,000 unique source-receiver pairs, we image isotropic P-wave velocity, radially anisotropic S-wave velocity and density via an iterative non-linear inversion that begins from a 1-D reference model. At each iteration, the full 3-D wavefield is determined through an anelastic Earth, accommodating effects of topography, bathymetry and ocean load. Our data selection aims to maximize sensitivity to deep structure by accounting for body wave arrivals separately. SASSY21, our final model after 87 iterations across seven period bands, is able to explain true-amplitude data from events and receivers not included in the inversion. The trade-off between inversion parameters is estimated through an analysis of the Hessian-vector product. SASSY21 reveals detailed anomalies down to the mantle transition zone, including multiple subduction zones. The most prominent feature is the (Indo-)Australian plate descending beneath Indonesia, which is imaged as one continuous slab along the 180° curvature of the Banda Arc. The tomography confirms the existence of a hole in the slab beneath Mount Tambora and locates a high S-wave velocity zone beneath northern Borneo that may be associated with subduction termination in the mid-late Miocene. A previously undiscovered feature beneath the east coast of Borneo is also revealed, which may be a signature of post-subduction processes, delamination or underthrusting from the formation of Sulawesi.Plain Language Summary Southeast Asia is one of the world's most tectonically active regions, as evidenced by frequent large earthquakes and volcanic eruptions. We present a large-scale 3-D seismic structural model of this region down to a depth of 800 km that reveals a variety of primary features, including beneath the poorly understood islands of Borneo and Sulawesi. This is possible thanks to the use of a sizable data set of earthquakes recorded by a large number of permanent and temporary stations located in Southeast Asia, and advanced imaging methodology that is better able to capture the true physics of seismic wave propagation compared to more traditional methods. Our new model is capable of resolving variations in seismic properties associated with ongoing subduction (when one tectonic plate descends into the mantle below another plate), particularly along the northern margin of the Australian plate beneath the Sunda Arc. More subtle anomalies associated with remnant subduction, which correspond to plate fragments that remain once subduction stops, can also be imaged. These results are important for achieving a better understanding of the subduction cycle, which plays a central role in plate tectonics, and has important implications for, among other things, the evolut...

show abstract

Crustal and upper mantle structure beneath South America from Rayleigh wave analysis

Corchete

2024

Geological Journal

View full text Add to dashboard Cite

A review of the S‐velocity structure beneath South America, for the crust and upper mantle, is performed using a recent methodology based on Rayleigh wave analysis, and a new 3D S‐velocity model (from 0 to 400 km depth) is achieved for this study area. The precise location and structure of the asthenosphere have been both determined from this new model, which have not been obtained in other previous studies, allowing to know how the different geological units that compose South America are delimited in terms of S‐velocity and lithosphere thickness. For example, the highest S‐velocities and the thickest lithosphere of the cratonic areas, are determined at the east of the Amazonian Craton and the São Francisco Craton. The lithosphere beneath the Guyana Shield is thinner than beneath the Central Brazil Shield, and the lithospheric root of the Amazonian Craton is determined deeper than the São Francisco Craton. The lithosphere at the east of the Central Brazil Shield is the thickest (~200‐km thick). Another interesting feature depicted in terms of S‐velocity and lithosphere thickness is the Transbrasiliano Lineament, which is determined in the crust and the upper mantle, confirming that it is not just a surface feature but a deep feature.

show abstract

Full Waveform Inversion Beneath the Central Andes: Insight Into the Dehydration of the Nazca Slab and Delamination of the Back‐Arc Lithosphere

Cited by 29 publications

References 159 publications

Controls of the lithospheric thermal field of an ocean-continent subduction zone: the southern Central Andes

Controls of the lithospheric thermal field of an ocean-continent subduction zone: the southern Central Andes

SASSY21: A 3-D seismic structural model of the lithosphere and underlying mantle beneath Southeast Asia from multi-scale adjoint waveform tomography

Crustal and upper mantle structure beneath South America from Rayleigh wave analysis

Contact Info

Product

Resources

About