The Grenville-age basement of the Andes

Ramos, Víctor A.

doi:10.1016/j.jsames.2009.09.004

Cited by 169 publications

(107 citation statements)

References 105 publications

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“…2). It is preserved in a series of basement inliers within the northern Andes of South America (e.g., Ramos, 2010, and references therein) as well as in the Oaxaquia terrane of Mexico, which has been placed between Baltica and Amazonia in the Rodinian reconstructions ( Oaxaquia terrane of Mexico, which would be accreted to northern Amazonia at that time (Solari et al, 2003). This event has been linked to collision between northern Amazonia and Baltica (Cardona et al, 2010;Ibanez-Mejia et al, 2011;Keppie et al, 2001;Keppie et al, 2004;Weber et al, 2010).…”

Section: North Amazonia -Putumayo Orogenmentioning

confidence: 99%

Laurentia-Baltica-Amazonia relations during Rodinia assembly

Cawood

Pisarevsky

2017

Precambrian Research

137

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Section: North Amazonia -Putumayo Orogenmentioning

confidence: 99%

Laurentia-Baltica-Amazonia relations during Rodinia assembly

Cawood

Pisarevsky

2017

Precambrian Research

137

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“…Ramos 1988Ramos , 2009Ramos et al 2002;Steenken et al 2004;Miller and Söllner 2005). Potential sutures indicating the margins of adjacent terranes, e.g.…”

Section: Regional Setting and Geodynamic Evolutionmentioning

confidence: 99%

Exhumation and uplift of the Sierras Pampeanas: preliminary implications from K–Ar fault gouge dating and low-T thermochronology in the Sierra de Comechingones (Argentina)

Löbens

Bense

Wemmer

et al. 2010

Int J Earth Sci (Geol Rundsch)

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The Sierras Pampeanas in central and northwestern Argentina constitute a distinct morphotectonic feature between 27°S and 33°S. The last stage of uplift and deformation in this area are interpreted to be closely related to the Andean flat-slab subduction of the Nazca plate beneath the South American plate. K-Ar fault gouge dating and low-temperature thermochronology along two transects within the Sierra de Comechingones reveal a minimum age for the onset of brittle deformation about 340 Ma, very low exhumation rates since Late Paleozoic time, as well as a total exhumation of about 2.3 km since the Late Cretaceous. New Ar-Ar ages (7.54-1.91 Ma) of volcanic rocks from the San Luis volcanic belt support the eastward propagation of the flat-slab magmatic front, confirming the onset of flat-slab related deformation in this region at 11.2 Ma. Although low-temperature thermochronology does not clearly constrain the signal of the Andean uplift, it is understood that the current structural relief related to the Comechingones range has been achieved after the exhumation of both fault walls (circa 80-70 Ma).

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“…To the south the composite Mesoproterozoic Arequipa-Antofalla block continues into Bolivia and Chile (Loewy et al 2004;Ramos 2008Ramos , 2010b and there sits atop South American cratonic crust (Figure 9 American margin and emplacement of the allochthons atop it. Some younger, even modern, thrusts near the eastern topographic break might relate to gravitational spreading of the overthickened and uplifted collisional crust.…”

Section: Regional Considerationsmentioning

confidence: 99%

“…Some younger, even modern, thrusts near the eastern topographic break might relate to gravitational spreading of the overthickened and uplifted collisional crust. Still farther south, relations are complex and incompletely resolved, but a >10 km thick synclinal accumulation of Jurassic to Late Cretaceous volcanic and allied rocks, collectively termed the Ocoite arc, sits unconformably upon deformed and metamorphosed Paleozoic rocks rocks of Chilenia, a Neoproterozoic basement terrrane (Levi and Aguirre 1981;Åberg et al 1984;Ramos 2010b). Basement outcrops are scarce and their relations to the more easterly Cuyania terrane are obscure (Ramos 2010b).…”

Section: Regional Considerationsmentioning

confidence: 99%

“…Still farther south, relations are complex and incompletely resolved, but a >10 km thick synclinal accumulation of Jurassic to Late Cretaceous volcanic and allied rocks, collectively termed the Ocoite arc, sits unconformably upon deformed and metamorphosed Paleozoic rocks rocks of Chilenia, a Neoproterozoic basement terrrane (Levi and Aguirre 1981;Åberg et al 1984;Ramos 2010b). Basement outcrops are scarce and their relations to the more easterly Cuyania terrane are obscure (Ramos 2010b). East of the volcanic rocks a well-developed, but largely eroded, foredeep basin and easterly vergent fold-thrust belt had developed by the Late Cretaceous (Morabito and Ramos 2012).…”

Section: Regional Considerationsmentioning

confidence: 99%

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Arc and Slab-Failure Magmatism in Cordilleran Batholiths I – The Cretaceous Coastal Batholith of Peru and its Role in South American Orogenesis and Hemispheric Subduction Flip

Hildebrand¹,

Whalen

2014

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We examined the temporal and spatial relations of rock units within the Western Cordillera of Peru where two Cretaceous basins, the Huarmey-Cañete and the West Peruvian Trough, were considered by previous workers to represent western and eastern parts respectively of the same marginal basin. The Huarmey-Cañete Trough, which sits on Mesoproterozoic basement of the Arequipa block, was filled with up to 9 km of Tithonian to Albian tholeiitic–calc-alkaline volcanic and volcaniclastic rocks. It shoaled to subaerial eastward. At 105–101 Ma the rocks were tightly folded and intruded during and just after the deformation by a suite of 103 ± 2 Ma mafic intrusions, and later in the interval 94–82 Ma by probable subduction-related plutons of the Coastal batholith. The West Peruvian Trough, which sits on Paleozoic metamorphic basement, comprised a west-facing siliciclastic-carbonate platform and adjacent basin filled with up to 5 km of sandstone, shale, marl and thinly bedded limestone deposited continuously throughout the Cretaceous. Rocks of the West Peruvian Trough were detached from their basement, folded and thrust eastward during the Late Cretaceous–Early Tertiary. Because the facies and facing directions of the two basins are incompatible, and their development and subjacent basements also distinct, the two basins could not have developed adjacent to one another. Based on thickness, composition and magmatic style, we interpret the magmatism of the Huarmey-Cañete Trough to represent a magmatic arc that shut down at about 105 Ma when the arc collided with an unknown terrane. We relate subsequent magmatism of the early 103 ± 2 Ma syntectonic mafic intrusions and dyke swarms to slab failure. The Huarmey-Cañete-Coastal batholithic block and its Mesoproterozoic basement remained offshore until 77 ± 5 Ma when it collided with, and was emplaced upon, the partially subducted western margin of South America to form the east-vergent Marañon fold–thrust belt. A major pulse of 73–62 Ma plutonism and dyke emplacement followed terminal collision and is interpreted to have been related to slab failure of the west-dipping South American lithosphere. Magmatism, 53 Ma and younger, followed terminal collision and was generated by eastward subduction of Pacific oceanic lithosphere beneath South America. Similar spatial and temporal relations exist over the length of both Americas and represent the terminal collision of an arc-bearing ribbon continent with the Americas during the Late Cretaceous–Early Tertiary Laramide event. It thus separated long-standing westward subduction from the younger period of eastward subduction characteristic of today. We speculate that the Cordilleran Ribbon Continent formed during the Mesozoic over a major zone of downwelling between Tuzo and Jason along the boundary of Panthalassic and Pacific oceanic plates.SOMMAIRENous avons étudié les relations spatiales et temporales des unités de roches dans la portion ouest de la Cordillère du Pérou, où deux bassins crétacés, la fosse d’accumulation de Huarmey-Cañete et la fosse d’accumulation péruvienne de l’ouest, ont été perçues par des auteurs précédents comme les portions ouest et est d’un même bassin de marge. La fosse de Huarmey-Cañete, qui repose sur le socle mésoprotérozoïque du bloc d’Arequipa, a été comblée par des couches de roches volcaniques tholéitiques – calco-alcalines de l’Albien au Thithonien atteignant 9 km d’épaisseur. Vers l’est, l’ensemble a fini par former des hauts fonds. Vers 105 à 101 Ma, les roches ont été plissées fortement puis recoupées par une suite d’intrusions vers 103 ± 2 Ma, durant et juste après la déformation, et plus tard dans l’intervalle 94 – 82 Ma, probablement par des plutons de subduction du batholite côtier. Quant à la fosse d’accumulation péruvienne de l’ouest, elle repose sur un socle métamorphique paléozoïque, et elle est constituée d’une plateforme silicoclastique – carbonate à pente ouest et d’un bassin contigu comblé par des grès, des schistes, des marnes et des calcaires finement laminés atteignant 5 km d’épaisseur et qui se sont déposés en continu durant tout le Crétacé. Les roches de la fosse d’accumulation péruvienne de l’ouest ont été décollées de leur socle, plissées et charriées vers l’est durant la fin du Crétacé et le début du Tertiaire. Parce que les facies et les profondeurs de sédimentation de ces deux fosses d’accumulation dont incompatibles, et que leur développement et leur socle sont différents, ces deux fosses ne peuvent pas s’être développées côte à côte. À cause de l’épaisseur accumulée, de sa composition et du style de son magmatisme, nous pensons que la fosse d’accumulation de Huarmey-Cañete représente un arc magmatique qui s’est éteinte vers 105 Ma, lorsque l’arc est entré en collision avec un terrane inconnu. Nous pensons que le magmatisme subséquent aux premières intrusions mafiques syntectoniques et aux réseaux de dykes de 103 ± 2 Ma sont à mettre au compte d’une rupture de plaque. Le bloc Huarmey-Cañete-batholitique côtier et son socle mésoprotérozoïque sont demeurés au large jusqu’à 77 ± 5 Ma, moment où il est entré en collision et a été poussé par-dessus la marge ouest sud-américaine partiellement subduite, pour ainsi former la zone de chevauchement de vergence est de Marañon. Nous croyons que la séquence majeure de plutonisme et d’intrusion de dykes qui a succédé à la collision finale à 73–62 Ma doit être reliée à une rupture de la plaque lithosphérique sud-américaine à pendage ouest. Le magmatisme de 53 Ma et plus récent qui a succédé à la collision finale, a été généré par la subduction vers l’est de la lithosphère océanique du Pacifique sous l’Amérique du Sud. Des relations temporelles et spatiales similaires qui existent tout le long des deux Amériques représentent la collision terminale d’un ruban continental d’arcs avec les Amériques durant la phase tectonique laramienne de la fin du Crétacé–début du Tertiaire. Elle a donc séparé la subduction vers l’ouest de longue date de la période de subduction vers l’est plus jeune caractérisant la situation actuelle. Nous considérons que le ruban continental de la Cordillère s’est constitué durant le Mésozoïque au-dessus d’une zone majeure de convection descendante entre Tuzo et Jason, le long de la limite entre les plaques océaniques Panthalassique et Pacifique.

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The Grenville-age basement of the Andes

Cited by 169 publications

References 105 publications

Laurentia-Baltica-Amazonia relations during Rodinia assembly

Laurentia-Baltica-Amazonia relations during Rodinia assembly

Exhumation and uplift of the Sierras Pampeanas: preliminary implications from K–Ar fault gouge dating and low-T thermochronology in the Sierra de Comechingones (Argentina)

Arc and Slab-Failure Magmatism in Cordilleran Batholiths I – The Cretaceous Coastal Batholith of Peru and its Role in South American Orogenesis and Hemispheric Subduction Flip

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