Cannibalization of a late Cambrian backarc in southern Peru: New insights into the assembly of southwestern Gondwana

Hodgin, Eben Blake; Gutiérrez-Marco, J. C.; Colmenar, Jorge; Macdonald, Francis A.; Carlotto, Vı́ctor; Crowley, James L.; Newmann, Justin

doi:10.1016/j.gr.2021.01.004

Cited by 12 publications

(3 citation statements)

References 103 publications

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“…Gutiérrez et al (2019), en función de consideraciones litoestratigráficas y del análisis de zonas fuentes de detrito (a partir de edades U/Pb en circones), plantean la canibalización y exhumación progresiva de los depósitos mesozoicos más occidentales de la Cuenca Oriente, incluyendo las formaciones Hollín y Napo. Los modelos de canibalización de márgenes continentales o cuenca de foreland consideran la generación de sistemas de cabalgamiento a partir de la evolución de pliegues de arrastre a sistemas de corrimientos (Swift y Thorne, 1991;Hodgin et al, 2021); también consideran la incorporación y deformación de secciones de la cuenca de foreland en la orogenia, a partir de múltiples cabalgamientos, y la propagación de la deformación hacia el interior de la margen debido a sistemas de empuje (Sagripanti et al, 2012;Chiocci y Casalbore, 2017). En estos sistemas, la tasa de desplazamiento vertical supera a la tasa de acortamiento horizontal (Brandes y Tanner, 2014).…”

Section: Discussionunclassified

Evidencias de canibalización de secuencias Cretácicas y Paleógenas de la Cuenca Oriente en la cuña orogénica de los Andes ecuatorianos

et al. 2021

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Al sureste de la Cordillera Real, en la sección del río Miriumi, rocas sedimentarias e ígneas metamorfoseadas fueron agrupadas sin discriminación en la Unidad Upano, y la falla Palanda-Méndez-Cosanga fue considerada un límite de terreno en anteriores investigaciones. El objetivo de esta investigación es caracterizar y discriminar rocas sedimentarias e ígneas metamorfoseadas de la Unidad Upano, de rocas sedimentarias de la Cuenca Oriente. Esta discriminación está soportada en datos litoestratigráficos, identificación de estructuras sedimentarias, registro de fósiles, estudios petrográficos y análisis de datos estructurales. Rocas meta-volcánicas y meta-pelíticas afloran en la parte occidental de la sección; mientras que hacia el este de la sección, secuencias estratodecrecientes de conglomerados de cuarzo, cuarzo-areniscas, lodolitas y areniscas con estructuras mareales; calizas mudstone y wackstone, lutitas negras con abundantes trazas de amonites y bivalvos son afectadas por un pliegue anticlinal. En el río Upano, calizas y lutitas fosilíferas son cubiertas en discordancia por limolitas multicolores y red beds. Considerando la descripción inicial de la Unidad Upano, se restringe a esta secuencia a rocas meta-volcánicas y meta-pelíticas de bajo grado de metamorfismo en facies de sub-esquistos verdes relacionadas a la dinámica regional. En este estudio, cuarzo-areniscas y lodolitas con estructuras mareales son incluidas en la Formación Hollín, calizas y lutitas con Inoceramus sp. y Harleites sp. (?) son asociadas a la Formación Napo; y secuencias de red beds son vinculadas a la Formación Tena. La presencia de bloques y escamas tectónicas compuestos por las formaciones Hollín, Napo y Tena de la Cuenca Oriente en el frente de la cuña orogénica, afectadas por zonas de corrimiento y pliegues de arrastre indican que la falla Palanda-Méndez-Cosanga, no constituye un límite de terreno entre secuencias metamórficas de la Cordillera Real y secuencias sedimentarias de la Cuenca Oriente. Al contrario, nuestros datos concuerdan con el modelo de canibalización de secuencias de foreland.

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Section: Discussionunclassified

Evidencias de canibalización de secuencias Cretácicas y Paleógenas de la Cuenca Oriente en la cuña orogénica de los Andes ecuatorianos

et al. 2021

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“…We pick CIMP rifting from 616 to 570 Ma (30). The margin ended with the Ediacaran-Late Cambrian oblique collision of the Pampean terranes and Arequipa from 545-520 Ma (160).…”

Section: Iapetan Margin Of Amazoniamentioning

confidence: 99%

“…We place the rift-drift transition at ~630 Ma. The margin was drowned by siliciclastic sedimentation between 545 and 520 Ma (160).…”

Section: Arequipamentioning

confidence: 99%

Hemispheric geochemical dichotomy of the mantle is a legacy of austral supercontinent assembly and deep subduction of continental crust

Jackson¹,

Macdonald²

2021

Preprint

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Oceanic hotspots with extreme enriched mantle radiogenic isotopic signatures—including high 87Sr/86Sr and low 143Nd/144Nd indicative of ancient subduction of continental crust—are restricted to the southern hemispheric mantle. However, the mechanisms responsible for concentrating subducted continental crust in the austral mantle are unknown. We show subduction of sediments and subduction eroded material, and lower continental crust delamination, cannot generate this spatially coherent austral domain. However, late Neoproterozoic to Paleozoic continental collisions—associated with the assembly of Gondwana and Pangea—were positioned predominantly in the southern hemisphere during the late Neoproterozoic appearance of widespread continental ultra-high-pressure (UHP, >2.7 gigapascals) metamorphic terranes, which marked the onset of deep subduction of upper continental crust. We propose that deep subduction of upper continental crust at ancient rifted-passive margins during austral supercontinent assembly, from 650-300 Ma, resulted in enhanced upper continental crust delivery into the southern hemisphere mantle. In contrast, EM domains are absent in boreal hotspots, for two reasons. First, continental crust subducted after 300—when the continents drifted into the northern hemisphere—has had insufficient time to return to the surface in plumes feeding northern hemisphere hotspots. Second, before the appearance of continental UHP rocks at 650 Ma, upper continental crust was not subducted to great depths, thus precluding its subduction into the northern hemisphere mantle during the Precambrian when continents may have been located in the northern hemisphere. Our model implies a recent formation of the austral EM domain, explains the geochemical dichotomy between austral and boreal hotspots, and may explain why austral hotspots outnumber boreal hotspots.

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Lower–Middle Ordovician brachiopods from the Eastern Cordillera of Peru: evidence of active faunal dispersal across Rheic and Iapetus oceans

Colmenar,

Chacaltana,

Gutiérrez‐Marco

2024

Papers in Palaeontology

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New Floian and early middle Darriwilian brachiopod assemblages of the San José Formation of the Eastern Cordillera of Peru are presented. A new genus and species, Apurimella santiagoi, and two new species, Phragmorthis henrylunae and Nocturnellia ashaninka, are described. The assemblages also contain additional characteristic taxa demonstrating links with other proto‐Andean localities (Peruvian Altiplano, Argentinian Eastern Cordillera, Famatina) as well as with some localities of Baltica (Estonia, Ingria, Norway), Ganderia (Anglesey, Tramore, Indian Bay, Summerford, Miramichi), peri‐Laurentia (Mayo, Svalbard) and Laurentia (Klamath Mountains). Those shared genera indicate dynamic faunal exchanges between the Peruvian Eastern Cordillera and these terranes during the Early–Middle Ordovician transition, suggesting active brachiopod dispersal mechanisms across the Rheic and Iapetus oceans. These connections seem to have still been active by the middle Darriwilian, as suggested by the presence of Phragmorthis in the Darriwilian assemblages of Cuyania and Laurentia. Similarly, the new Peruvian Nocturnellia species is of particular interest, given that this genus is likely to have originated in South China during the Floian, but extended its distribution to Avalonia and to high‐latitude peri‐Gondwana by the Dapingian. It thrived there until the middle Darriwilian, but by that time had also reached the proto‐Andean margin either via Avalonia across the Rheic Ocean or along the Gondwanan coast from high‐latitude settings. All of these occurrences improve our knowledge of Early–Middle Ordovician brachiopod faunas of the northern Central Andean Basin and their relationships with contemporaneous faunas worldwide.

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Cannibalization of a late Cambrian backarc in southern Peru: New insights into the assembly of southwestern Gondwana

Cited by 12 publications

References 103 publications

Evidencias de canibalización de secuencias Cretácicas y Paleógenas de la Cuenca Oriente en la cuña orogénica de los Andes ecuatorianos

Evidencias de canibalización de secuencias Cretácicas y Paleógenas de la Cuenca Oriente en la cuña orogénica de los Andes ecuatorianos

Hemispheric geochemical dichotomy of the mantle is a legacy of austral supercontinent assembly and deep subduction of continental crust

Lower–Middle Ordovician brachiopods from the Eastern Cordillera of Peru: evidence of active faunal dispersal across Rheic and Iapetus oceans

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