Thermometric studies form Algarrobo del Aguila granitoids, province of La Pampa
The granitic stocks of Algarrobo del Aguila, in the province of La Pampa, are assembled in "Complejo Intrusivo Algarrobo del Aguila" and they crop out in Las Matras Block forming smooth and small hills. Main outcrops of these Permian-Triassic granites are Puesto Los Cerros, Puesto Las Tina...
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2003
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00044822_v58_n4_p643_Montenegro http://hdl.handle.net/20.500.12110/paper_00044822_v58_n4_p643_Montenegro |
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paper:paper_00044822_v58_n4_p643_Montenegro2023-06-08T14:25:43Z Thermometric studies form Algarrobo del Aguila granitoids, province of La Pampa Alkali feldspar Fluid inclusions Shallow granites Variety of textures crystallization fluid inclusion granitoid Permian Triassic Argentina La Pampa South America Western Hemisphere World The granitic stocks of Algarrobo del Aguila, in the province of La Pampa, are assembled in "Complejo Intrusivo Algarrobo del Aguila" and they crop out in Las Matras Block forming smooth and small hills. Main outcrops of these Permian-Triassic granites are Puesto Los Cerros, Puesto Las Tinajeras and Cerro Colorado. The isolated outcrops of the Chos Malal monzogranite are close to the border with the province of Mendoza. Two new K/Ar whole rock ages yielded 256.8 ± 5.5 Ma for the Cerro Colorado aplite and 197.9 ± 3.9 Ma for the Puesto Los Cerros aplite. The granites show a wide textural variety, from fully plutonic to volcanic ones indicating a quick process of crystallization in a high level of the crust. Quartz crystallized in different modes. Complex composition fluids (H2O-NaCl-CO 2) with high salinity, were captured from 370 to 260°C in megacrysts. The CO2 did not pass 0.04% molar. The miarolitic quartz crystallized between 335 and 235oC, and the quartz of the veins between 330 to 300oC, both with salinities to 14 wt % eq. NaCl. The K-feldspars have intermediate values suggesting rapid cooling below 400°C temperature. Those temperatures are compatible with microcline crystallization without "tartan" twin. The occurrence of minerals as fluorite, apatite, and tourmaline supports the hypothesis of a shallow intrusion level for these rocks. © 2003 Asociación Geológica Argentina. 2003 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00044822_v58_n4_p643_Montenegro http://hdl.handle.net/20.500.12110/paper_00044822_v58_n4_p643_Montenegro |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Alkali feldspar Fluid inclusions Shallow granites Variety of textures crystallization fluid inclusion granitoid Permian Triassic Argentina La Pampa South America Western Hemisphere World |
| spellingShingle |
Alkali feldspar Fluid inclusions Shallow granites Variety of textures crystallization fluid inclusion granitoid Permian Triassic Argentina La Pampa South America Western Hemisphere World Thermometric studies form Algarrobo del Aguila granitoids, province of La Pampa |
| topic_facet |
Alkali feldspar Fluid inclusions Shallow granites Variety of textures crystallization fluid inclusion granitoid Permian Triassic Argentina La Pampa South America Western Hemisphere World |
| description |
The granitic stocks of Algarrobo del Aguila, in the province of La Pampa, are assembled in "Complejo Intrusivo Algarrobo del Aguila" and they crop out in Las Matras Block forming smooth and small hills. Main outcrops of these Permian-Triassic granites are Puesto Los Cerros, Puesto Las Tinajeras and Cerro Colorado. The isolated outcrops of the Chos Malal monzogranite are close to the border with the province of Mendoza. Two new K/Ar whole rock ages yielded 256.8 ± 5.5 Ma for the Cerro Colorado aplite and 197.9 ± 3.9 Ma for the Puesto Los Cerros aplite. The granites show a wide textural variety, from fully plutonic to volcanic ones indicating a quick process of crystallization in a high level of the crust. Quartz crystallized in different modes. Complex composition fluids (H2O-NaCl-CO 2) with high salinity, were captured from 370 to 260°C in megacrysts. The CO2 did not pass 0.04% molar. The miarolitic quartz crystallized between 335 and 235oC, and the quartz of the veins between 330 to 300oC, both with salinities to 14 wt % eq. NaCl. The K-feldspars have intermediate values suggesting rapid cooling below 400°C temperature. Those temperatures are compatible with microcline crystallization without "tartan" twin. The occurrence of minerals as fluorite, apatite, and tourmaline supports the hypothesis of a shallow intrusion level for these rocks. © 2003 Asociación Geológica Argentina. |
| title |
Thermometric studies form Algarrobo del Aguila granitoids, province of La Pampa |
| title_short |
Thermometric studies form Algarrobo del Aguila granitoids, province of La Pampa |
| title_full |
Thermometric studies form Algarrobo del Aguila granitoids, province of La Pampa |
| title_fullStr |
Thermometric studies form Algarrobo del Aguila granitoids, province of La Pampa |
| title_full_unstemmed |
Thermometric studies form Algarrobo del Aguila granitoids, province of La Pampa |
| title_sort |
thermometric studies form algarrobo del aguila granitoids, province of la pampa |
| publishDate |
2003 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00044822_v58_n4_p643_Montenegro http://hdl.handle.net/20.500.12110/paper_00044822_v58_n4_p643_Montenegro |
| _version_ |
1768543398280560640 |