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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| Formato: | JOUR |
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| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_00044822_v75_n3_p396_Remesal |
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todo:paper_00044822_v75_n3_p396_Remesal2023-10-03T13:59:26Z Basalts of the northern Somún Curá Plateau. Río Negro province Remesal, M. Cordenons, P.D. Alric, V. Cerredo, M.E. 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. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00044822_v75_n3_p396_Remesal |
| institution |
Universidad de Buenos Aires |
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I-28 |
| repository_str |
R-134 |
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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 Remesal, M. Cordenons, P.D. Alric, V. Cerredo, M.E. 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. |
| format |
JOUR |
| author |
Remesal, M. Cordenons, P.D. Alric, V. Cerredo, M.E. |
| author_facet |
Remesal, M. Cordenons, P.D. Alric, V. Cerredo, M.E. |
| author_sort |
Remesal, M. |
| 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 |
| url |
http://hdl.handle.net/20.500.12110/paper_00044822_v75_n3_p396_Remesal |
| work_keys_str_mv |
AT remesalm basaltsofthenorthernsomuncuraplateaurionegroprovince AT cordenonspd basaltsofthenorthernsomuncuraplateaurionegroprovince AT alricv basaltsofthenorthernsomuncuraplateaurionegroprovince AT cerredome basaltsofthenorthernsomuncuraplateaurionegroprovince |
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1807314701290307584 |