Geochemical and tectonic evolution of Late Cretaceous to early Paleocene magmatism along the Southern Central Andes (35-36°S)

Late Cretaceous-early Paleocene magmatism at Southern Central Andes is represented by incomplete and not well-preserved outcrops. A recent U-Pb age from a volcano-sedimentary sequence in the southern Andes of Mendoza province (35°30′S) led to identify Late Mesozoic-Early Cenozoic magmatism, which wa...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Iannelli, S.B., Fennell, L.M., Litvak, V.D., Lucía, F.P., Alfonso, E., Andrés, F.
Formato: JOUR
Materias:
Arc-like volcanism
Enriched source
Los Á
Ngeles unit
Ridge subduction
Slab-window
Cretaceous
igneous geochemistry
magmatism
slab
subduction zone
tectonic evolution
volcanism
Andes
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_08959811_v87_n_p139_Iannelli
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id todo:paper_08959811_v87_n_p139_Iannelli
record_format dspace
spelling todo:paper_08959811_v87_n_p139_Iannelli2023-10-03T15:43:37Z Geochemical and tectonic evolution of Late Cretaceous to early Paleocene magmatism along the Southern Central Andes (35-36°S) Iannelli, S.B. Fennell, L.M. Litvak, V.D. Lucía, F.P. Alfonso, E. Andrés, F. Arc-like volcanism Enriched source Los Á Ngeles unit Ridge subduction Slab-window Cretaceous igneous geochemistry magmatism slab subduction zone tectonic evolution volcanism Andes Late Cretaceous-early Paleocene magmatism at Southern Central Andes is represented by incomplete and not well-preserved outcrops. A recent U-Pb age from a volcano-sedimentary sequence in the southern Andes of Mendoza province (35°30′S) led to identify Late Mesozoic-Early Cenozoic magmatism, which was not previously registered. We focus on the petrological and geochemical characterization of this sequence, informally named as Los Ángeles Unit (67 Ma). This magmatic association comprises basaltic and andesitic lava flows interbedded with volcanic breccias and lithic sandstones; all of them intruded by subvertical basaltic dykes. Geochemically, the volcanic rocks are mainly tholeiitic with an arc-like signature and high LILE relative to HFSE content. A general enrichment in incompatible elements is seen towards the upper and younger lava flows, associated with a more alkaline character in the youngest ones. A regional comparison among Los Ángeles Unit and other Late Cretaceous-Paleocene arc magmatic series along the Southern Central Andes (35°-41°S) shows that the studied sequence has a weaker arc-like signature and less slab-fluid influence than in coeval southern units. This contrasting geochemical behavior is proposed to be a consequence of the subduction of the Farallon-Aluk spreading ridge beneath the studied latitudes (35°30′S) at ∼70 Ma. Thus, the enrichment seen along the volcanic sequence together with the alkaline-like signature seen in the younger volcanic levels of Los Ángeles Unit would be related to the subduction of anhydrous oceanic crust and potentially the incipient development of a slab window. Similar geochemical features are seen to the south in the magmatic expressions of the northern Eocene Pilcaniyeu Belt outcrops (∼40°S; 44 Ma), as they show a limited arc-like signature and an intraplate-like composition. The segmented geometry of the Farallon-Aluk spreading ridge and its progressive migration from north to south is considered to be the main cause of the development of contrasting magmatic associations during time and space. © 2017 Elsevier Ltd JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_08959811_v87_n_p139_Iannelli
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Arc-like volcanism
Enriched source
Los Á
Ngeles unit
Ridge subduction
Slab-window
Cretaceous
igneous geochemistry
magmatism
slab
subduction zone
tectonic evolution
volcanism
Andes
spellingShingle Arc-like volcanism
Enriched source
Los Á
Ngeles unit
Ridge subduction
Slab-window
Cretaceous
igneous geochemistry
magmatism
slab
subduction zone
tectonic evolution
volcanism
Andes
Iannelli, S.B.
Fennell, L.M.
Litvak, V.D.
Lucía, F.P.
Alfonso, E.
Andrés, F.
Geochemical and tectonic evolution of Late Cretaceous to early Paleocene magmatism along the Southern Central Andes (35-36°S)
topic_facet Arc-like volcanism
Enriched source
Los Á
Ngeles unit
Ridge subduction
Slab-window
Cretaceous
igneous geochemistry
magmatism
slab
subduction zone
tectonic evolution
volcanism
Andes
description Late Cretaceous-early Paleocene magmatism at Southern Central Andes is represented by incomplete and not well-preserved outcrops. A recent U-Pb age from a volcano-sedimentary sequence in the southern Andes of Mendoza province (35°30′S) led to identify Late Mesozoic-Early Cenozoic magmatism, which was not previously registered. We focus on the petrological and geochemical characterization of this sequence, informally named as Los Ángeles Unit (67 Ma). This magmatic association comprises basaltic and andesitic lava flows interbedded with volcanic breccias and lithic sandstones; all of them intruded by subvertical basaltic dykes. Geochemically, the volcanic rocks are mainly tholeiitic with an arc-like signature and high LILE relative to HFSE content. A general enrichment in incompatible elements is seen towards the upper and younger lava flows, associated with a more alkaline character in the youngest ones. A regional comparison among Los Ángeles Unit and other Late Cretaceous-Paleocene arc magmatic series along the Southern Central Andes (35°-41°S) shows that the studied sequence has a weaker arc-like signature and less slab-fluid influence than in coeval southern units. This contrasting geochemical behavior is proposed to be a consequence of the subduction of the Farallon-Aluk spreading ridge beneath the studied latitudes (35°30′S) at ∼70 Ma. Thus, the enrichment seen along the volcanic sequence together with the alkaline-like signature seen in the younger volcanic levels of Los Ángeles Unit would be related to the subduction of anhydrous oceanic crust and potentially the incipient development of a slab window. Similar geochemical features are seen to the south in the magmatic expressions of the northern Eocene Pilcaniyeu Belt outcrops (∼40°S; 44 Ma), as they show a limited arc-like signature and an intraplate-like composition. The segmented geometry of the Farallon-Aluk spreading ridge and its progressive migration from north to south is considered to be the main cause of the development of contrasting magmatic associations during time and space. © 2017 Elsevier Ltd
format JOUR
author Iannelli, S.B.
Fennell, L.M.
Litvak, V.D.
Lucía, F.P.
Alfonso, E.
Andrés, F.
author_facet Iannelli, S.B.
Fennell, L.M.
Litvak, V.D.
Lucía, F.P.
Alfonso, E.
Andrés, F.
author_sort Iannelli, S.B.
title Geochemical and tectonic evolution of Late Cretaceous to early Paleocene magmatism along the Southern Central Andes (35-36°S)
title_short Geochemical and tectonic evolution of Late Cretaceous to early Paleocene magmatism along the Southern Central Andes (35-36°S)
title_full Geochemical and tectonic evolution of Late Cretaceous to early Paleocene magmatism along the Southern Central Andes (35-36°S)
title_fullStr Geochemical and tectonic evolution of Late Cretaceous to early Paleocene magmatism along the Southern Central Andes (35-36°S)
title_full_unstemmed Geochemical and tectonic evolution of Late Cretaceous to early Paleocene magmatism along the Southern Central Andes (35-36°S)
title_sort geochemical and tectonic evolution of late cretaceous to early paleocene magmatism along the southern central andes (35-36°s)
url http://hdl.handle.net/20.500.12110/paper_08959811_v87_n_p139_Iannelli
work_keys_str_mv AT iannellisb geochemicalandtectonicevolutionoflatecretaceoustoearlypaleocenemagmatismalongthesoutherncentralandes3536s
AT fennelllm geochemicalandtectonicevolutionoflatecretaceoustoearlypaleocenemagmatismalongthesoutherncentralandes3536s
AT litvakvd geochemicalandtectonicevolutionoflatecretaceoustoearlypaleocenemagmatismalongthesoutherncentralandes3536s
AT luciafp geochemicalandtectonicevolutionoflatecretaceoustoearlypaleocenemagmatismalongthesoutherncentralandes3536s
AT alfonsoe geochemicalandtectonicevolutionoflatecretaceoustoearlypaleocenemagmatismalongthesoutherncentralandes3536s
AT andresf geochemicalandtectonicevolutionoflatecretaceoustoearlypaleocenemagmatismalongthesoutherncentralandes3536s
_version_ 1782026748212281344

Ejemplares similares