Multiple styles and scales of lithospheric foundering beneath the Puna Plateau, central Andes

Beck, S. L.; Zandt, G.; Ward, Kevin M.; Scire, A. C.

doi:10.1130/2015.1212(03)

Cited by 40 publications

(81 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Because the GF is roughly the western limit of the later Appalachian orogen in the SEUS [ Thomas , ], the reworked nature of the lithosphere to its east may have been more susceptible to instability following multiple episodes of subduction and lithospheric shortening. This sort of piecemeal delamination beneath large orogens is a well‐documented occurrence [ Beck et al ., ].…”

Section: Discussionmentioning

confidence: 99%

Relationship between observed upper mantle structures and recent tectonic activity across the Southeastern United States

et al. 2016

View full text Add to dashboard Cite

The lithospheric structure of the Southeastern United States is a product of earlier episodes of continental collision and breakup. The region is located in the interior of the North American Plate, away from active plate margins. However, there is ongoing tectonism in the region with multiple zones of seismicity, uplifting arches, and Cenozoic intraplate volcanism. The mechanisms controlling this activity and the state of stress remain enigmatic. Two important factors are plate strength and preexisting, inherited structures. Here we present new tomographic images of the upper mantle beneath the Southeastern United States, revealing large‐scale structural variations in the upper mantle. Examples include the relatively thick lithospheric mantle of stable North America that abruptly thins beneath the Paleozoic Appalachian orogeny, and the slow upper mantle of the Proterozoic Reelfoot rift. Our results also indicate fast seismic velocity patterns that can be interpreted as ongoing lithospheric foundering. This provides a viable explanation for seismicity, uplifting, and young intraplate volcanism. We postulate that not only tectonic inheritance but also continuing lithospheric foundering may control the ongoing activity of the region long after it became a passive margin. Based on distinct variations in the geometry and thickness of the lithospheric mantle and foundered lithosphere, we propose that piecemeal delamination has occurred beneath the region throughout the Cenozoic, removing a significant amount of reworked/deformed mantle lithosphere. Ongoing lithospheric foundering beneath the eastern margin of stable North America explains significant variations in thickness of lithospheric mantle across the former Grenville deformation front.

show abstract

Section: Discussionmentioning

confidence: 99%

Relationship between observed upper mantle structures and recent tectonic activity across the Southeastern United States

et al. 2016

View full text Add to dashboard Cite

show abstract

“…. Beginning with the westward retreating delamination of a weak mantle lithosphere and dense lower crust after an increase in the dip of the subducting slab at 16 Ma (refs 5, 7), hot (low density) asthenosphere flows under the previously thickened orogenic crust causing uplift from the gain in gravitational potential energy50 (Fig. 7a).…”

Section: Discussionmentioning

confidence: 99%

“…The conceptual model underlying the mathematical one assumes that the crust here is thickening from the addition of material at its base. In the case of our study, we assume that the crust is being added by mantle-derived melt as upwelling warm asthenosphere replaces the lithosphere that was removed through delamination7. We can therefore model the original contribution to crustal thickening from the accumulation of mantle-derived melt as a convolution of the topographic load profile and the isostatic response function, which is more simply solved through multiplication in frequency space:…”

Section: Methodsmentioning

confidence: 99%

“…The thin lithosphere beneath the APVC may result from convective removal567, a potentially cyclical process8 that has contributed to pulses of rapid surface uplift throughout the history of the Central Andes9. The mantle heat flux associated with lithospheric removal is thought to be responsible for the flare-up of large-volume ignimbrites5610, collectively known as the Altiplano-Puna Volcanic Complex (APVC)11, since ∼11 million years ago (Ma)12.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Surface uplift in the Central Andes driven by growth of the Altiplano Puna Magma Body

et al. 2016

Self Cite

View full text Add to dashboard Cite

The Altiplano-Puna Magma Body (APMB) in the Central Andes is the largest imaged magma reservoir on Earth, and is located within the second highest orogenic plateau on Earth, the Altiplano-Puna. Although the APMB is a first-order geologic feature similar to the Sierra Nevada batholith, its role in the surface uplift history of the Central Andes remains uncertain. Here we show that a long-wavelength topographic dome overlies the seismically measured extent of the APMB, and gravity data suggest that the uplift is isostatically compensated. Isostatic modelling of the magmatic contribution to dome growth yields melt volumes comparable to those estimated from tomography, and suggests that the APMB growth rate exceeds the peak Cretaceous magmatic flare-up in the Sierran batholith. Our analysis reveals that magmatic addition may provide a contribution to surface uplift on par with lithospheric removal, and illustrates that surface topography may help constrain the magnitude of pluton-scale melt production.

show abstract

“…Lithospheric delamination has been long postulated as a contributing mechanism to the growth of the central Andes [ Kay and Kay , ; Kay et al ., ; Beck and Zandt , ; McQuarrie et al ., ; Asch et al ., ; Garzione et al ., ; Ghosh et al ., ; DeCelles et al ., ], but only recently has the data coverage and methodology become available to investigate the structure of the uppermost mantle in sufficient detail [e.g., Calixto et al ., ; Beck et al ., ; Scire et al ., ]. Although seismic models of the uppermost mantle alone cannot determine the timing and evolution of delamination events, they are particularly useful in discriminating against different models and stages of lithospheric delamination.…”

Section: Discussionmentioning

confidence: 99%

Lithospheric structure beneath the northern Central Andean Plateau from the joint inversion of ambient noise and earthquake‐generated surface waves

et al. 2016

Self Cite

View full text Add to dashboard Cite

The Central Andean Plateau (CAP), as defined by elevations in excess of 3 km, extends over 1800 km along the active South American Cordilleran margin making it the second largest active orogenic plateau on Earth. The uplift history of this high Plateau, with an average elevation around 4 km above sea level, remains uncertain as paleoelevation studies along the CAP suggest a complex, nonuniform uplift history. As part of the Central Andean Uplift and the Geodynamics of High Topography (CAUGHT) project, we image the S wave velocity structure of the crust and upper mantle using surface waves measured from ambient noise and teleseismic earthquakes to investigate the upper mantle component of plateau uplift. We observe three main features in our S wave velocity model including (1) a positive velocity perturbation associated with the subducting Nazca slab; (2) a negative velocity perturbation below the sub‐Andean crust that we interpret as anisotropic Brazilian cratonic lithosphere; and (3) a high‐velocity feature in the mantle above the slab that extends along the length of the Altiplano from the base of the Moho to a depth of ~120 km. A strong spatial correlation exists between the lateral extent of this high‐velocity feature and the relatively lower elevations of the Altiplano basin suggesting a potential relationship. Determining if this high‐velocity feature represents a small lithospheric root or foundering of orogenic lithosphere requires more integration of observations, but either interpretation implies a strong geodynamic connection with the uppermost mantle and the current topography of the northern CAP.

show abstract

Multiple styles and scales of lithospheric foundering beneath the Puna Plateau, central Andes

Cited by 40 publications

References 0 publications

Relationship between observed upper mantle structures and recent tectonic activity across the Southeastern United States

Relationship between observed upper mantle structures and recent tectonic activity across the Southeastern United States

Surface uplift in the Central Andes driven by growth of the Altiplano Puna Magma Body

Lithospheric structure beneath the northern Central Andean Plateau from the joint inversion of ambient noise and earthquake‐generated surface waves

Contact Info

Product

Resources

About