Basalts of the northern Somún Curá Plateau. Río Negro province

The basaltic Somún Curá plateau is one of the most outstanding geoforms in the northern Extrandean Patagonia; it corresponds to a Paleogene-Neogene volcanic association. The northeastern sector displays a strongly irregular outline on map view; cross sections expose a stacking of basaltic lava flows...

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Guardado en:
Detalles Bibliográficos
Publicado: 2018
Materias:
Age
Basalts
Inflated lava flows
Liquid immiscibility texture
Somún Curá plateau
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00044822_v75_n3_p396_Remesal
http://hdl.handle.net/20.500.12110/paper_00044822_v75_n3_p396_Remesal
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_00044822_v75_n3_p396_Remesal
record_format dspace
spelling paper:paper_00044822_v75_n3_p396_Remesal2023-06-08T14:27:05Z Basalts of the northern Somún Curá Plateau. Río Negro province Age Basalts Inflated lava flows Liquid immiscibility texture Somún Curá plateau The basaltic Somún Curá plateau is one of the most outstanding geoforms in the northern Extrandean Patagonia; it corresponds to a Paleogene-Neogene volcanic association. The northeastern sector displays a strongly irregular outline on map view; cross sections expose a stacking of basaltic lava flows thinning northwards. To the south the basaltic volcanic sequence is covered by a younger basaltic to trachytic assemblage of the Alta Sierra de Somún Curá Volcanic Complex. Typical outcrop structures of inflated flows were recognized, as well as some intra-flow features (spiracles, lava tunnels). A new 40 Ar/ 39 Ar age is presented for the studied basalts which yielded 21,6 ± 0,5 Ma. Whole rock compositions correspond to subalkaline basalts and basaltic andesites, with low-to middle K. The studied flows correspond to olivine basalts, aphyric or poorly porphyric, composed of: olivine, clinopyroxene, plagioclase, Fe-Ti oxides and a glassy mesostasis. High temperature iddingsite replacements are common in olivine. A semiquantitative compositional characterization is presented for the main framework minerals. Classical textures indicating liquid immiscibility are observed in the mesostasis accompanied by partial devitrification (globules, skeletal crystals, etc.). A semiquantitative estimation of the unmixed siliceous liquid was acquired indicating a subalkaline rhyolite composition, of intermediate K 2 O content. © 2018, Asociacion Geologica Argentina. All rights reserved. 2018 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00044822_v75_n3_p396_Remesal http://hdl.handle.net/20.500.12110/paper_00044822_v75_n3_p396_Remesal
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Age
Basalts
Inflated lava flows
Liquid immiscibility texture
Somún Curá plateau
spellingShingle Age
Basalts
Inflated lava flows
Liquid immiscibility texture
Somún Curá plateau
Basalts of the northern Somún Curá Plateau. Río Negro province
topic_facet Age
Basalts
Inflated lava flows
Liquid immiscibility texture
Somún Curá plateau
description The basaltic Somún Curá plateau is one of the most outstanding geoforms in the northern Extrandean Patagonia; it corresponds to a Paleogene-Neogene volcanic association. The northeastern sector displays a strongly irregular outline on map view; cross sections expose a stacking of basaltic lava flows thinning northwards. To the south the basaltic volcanic sequence is covered by a younger basaltic to trachytic assemblage of the Alta Sierra de Somún Curá Volcanic Complex. Typical outcrop structures of inflated flows were recognized, as well as some intra-flow features (spiracles, lava tunnels). A new 40 Ar/ 39 Ar age is presented for the studied basalts which yielded 21,6 ± 0,5 Ma. Whole rock compositions correspond to subalkaline basalts and basaltic andesites, with low-to middle K. The studied flows correspond to olivine basalts, aphyric or poorly porphyric, composed of: olivine, clinopyroxene, plagioclase, Fe-Ti oxides and a glassy mesostasis. High temperature iddingsite replacements are common in olivine. A semiquantitative compositional characterization is presented for the main framework minerals. Classical textures indicating liquid immiscibility are observed in the mesostasis accompanied by partial devitrification (globules, skeletal crystals, etc.). A semiquantitative estimation of the unmixed siliceous liquid was acquired indicating a subalkaline rhyolite composition, of intermediate K 2 O content. © 2018, Asociacion Geologica Argentina. All rights reserved.
title Basalts of the northern Somún Curá Plateau. Río Negro province
title_short Basalts of the northern Somún Curá Plateau. Río Negro province
title_full Basalts of the northern Somún Curá Plateau. Río Negro province
title_fullStr Basalts of the northern Somún Curá Plateau. Río Negro province
title_full_unstemmed Basalts of the northern Somún Curá Plateau. Río Negro province
title_sort basalts of the northern somún curá plateau. río negro province
publishDate 2018
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00044822_v75_n3_p396_Remesal
http://hdl.handle.net/20.500.12110/paper_00044822_v75_n3_p396_Remesal
_version_ 1768543160312528896

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