Petrology and geochemistry of meta-ultramafic rocks in the Paleozoic Granjeno Schist, northeastern Mexico: Remnants of Pangaea ocean floor
Abstract: The Granjeno Schist is a meta-volcanosedimentary upper Paleozoic complex in northeastern Mexico. We suggest different tectonic settings for metamorphism of its serpentinite and talc-bearing rocks based on petrographic and geochemical compositions. According to the REE ratios (LaN/YbN = 0.5...
| Autores principales: | , , , , , , , |
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| Formato: | Artículo |
| Lenguaje: | inglés |
| Publicado: |
2017
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| Acceso en línea: | http://eprints.uanl.mx/18249/1/540.pdf |
| _version_ | 1824415185042931712 |
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| author | Torres Sánchez, Sonia Alejandra Augustsson, Carita Jenchen, Uwe Barboza Gudiño, José Rafael Alemán Gallardo, Eduardo Alejandro Ramírez Fernández, Juan Alonso Torres Sánchez, Darío Abratis, Michael |
| author_facet | Torres Sánchez, Sonia Alejandra Augustsson, Carita Jenchen, Uwe Barboza Gudiño, José Rafael Alemán Gallardo, Eduardo Alejandro Ramírez Fernández, Juan Alonso Torres Sánchez, Darío Abratis, Michael |
| author_sort | Torres Sánchez, Sonia Alejandra |
| collection | Repositorio Institucional |
| description | Abstract: The Granjeno Schist is a meta-volcanosedimentary upper Paleozoic complex in northeastern Mexico. We suggest different tectonic settings for metamorphism of its serpentinite and talc-bearing rocks based on petrographic and geochemical compositions. According to the REE ratios (LaN/YbN = 0.51–20.0 and LaN/SmN = 0.72–9.1) and the enrichment in the highly incompatible elements Cs (0.1 ppm), U (2.8 ppm), and Zr (60 ppm) as well as depletion in Ba (1 – 15 ppm), Sr (1–184ppm),Pb(0.1–14ppm),andCe(0.1–1.9ppm)the rocks have mid-ocean ridge and subduction zones characteristics.TheserpentinitecontainsAl-chromite,ferrian chromiteandmagnetite.TheAl-chromiteischaracterized byCr#of0.48to0.55suggestingaMORBorigin,andCr#of 0.93 to 1.00 for the ferrian chromite indicates a prograde metamorphism.Weproposeatleasttwoserpentinization stagesoflithosphericmantlefortheultramaficrockofthe GranjenoSchist,(1)afirstinanocean-floorenvironment atsub-greenschisttogreenschistfaciesconditionsand(2) later a serpentinization phase related to the progressive replacement of spinel by ferrian chromite and magnetite atgreenschisttolowamphibolitefaciesconditionsduring regional metamorphism. The second serpentinization phase took place in an active continental margin during the Pennsylvanian. We propose that the origin of the ultramaficrocksisrelated toanobductionandaccretional eventatthewesternmarginofPangea. Keywords: ultramafic rocks; serpentinite; Granjeno Schist;northeasternMexico,Gondwana,Pangea |
| format | Article |
| id | eprints-18249 |
| institution | UANL |
| language | English |
| publishDate | 2017 |
| record_format | eprints |
| spelling | eprints-182492020-05-01T15:21:34Z http://eprints.uanl.mx/18249/ Petrology and geochemistry of meta-ultramafic rocks in the Paleozoic Granjeno Schist, northeastern Mexico: Remnants of Pangaea ocean floor Torres Sánchez, Sonia Alejandra Augustsson, Carita Jenchen, Uwe Barboza Gudiño, José Rafael Alemán Gallardo, Eduardo Alejandro Ramírez Fernández, Juan Alonso Torres Sánchez, Darío Abratis, Michael SD Ciencia forestal Abstract: The Granjeno Schist is a meta-volcanosedimentary upper Paleozoic complex in northeastern Mexico. We suggest different tectonic settings for metamorphism of its serpentinite and talc-bearing rocks based on petrographic and geochemical compositions. According to the REE ratios (LaN/YbN = 0.51–20.0 and LaN/SmN = 0.72–9.1) and the enrichment in the highly incompatible elements Cs (0.1 ppm), U (2.8 ppm), and Zr (60 ppm) as well as depletion in Ba (1 – 15 ppm), Sr (1–184ppm),Pb(0.1–14ppm),andCe(0.1–1.9ppm)the rocks have mid-ocean ridge and subduction zones characteristics.TheserpentinitecontainsAl-chromite,ferrian chromiteandmagnetite.TheAl-chromiteischaracterized byCr#of0.48to0.55suggestingaMORBorigin,andCr#of 0.93 to 1.00 for the ferrian chromite indicates a prograde metamorphism.Weproposeatleasttwoserpentinization stagesoflithosphericmantlefortheultramaficrockofthe GranjenoSchist,(1)afirstinanocean-floorenvironment atsub-greenschisttogreenschistfaciesconditionsand(2) later a serpentinization phase related to the progressive replacement of spinel by ferrian chromite and magnetite atgreenschisttolowamphibolitefaciesconditionsduring regional metamorphism. The second serpentinization phase took place in an active continental margin during the Pennsylvanian. We propose that the origin of the ultramaficrocksisrelated toanobductionandaccretional eventatthewesternmarginofPangea. Keywords: ultramafic rocks; serpentinite; Granjeno Schist;northeasternMexico,Gondwana,Pangea 2017-07-05 Article PeerReviewed text en cc_by_nc_nd http://eprints.uanl.mx/18249/1/540.pdf http://eprints.uanl.mx/18249/1.haspreviewThumbnailVersion/540.pdf Torres Sánchez, Sonia Alejandra y Augustsson, Carita y Jenchen, Uwe y Barboza Gudiño, José Rafael y Alemán Gallardo, Eduardo Alejandro y Ramírez Fernández, Juan Alonso y Torres Sánchez, Darío y Abratis, Michael (2017) Petrology and geochemistry of meta-ultramafic rocks in the Paleozoic Granjeno Schist, northeastern Mexico: Remnants of Pangaea ocean floor. Open Geosciences, 9 (1). pp. 361-384. ISSN 2391-5447 http://doi.org/10.1515/geo-2017-0029 doi:10.1515/geo-2017-0029 |
| spellingShingle | SD Ciencia forestal Torres Sánchez, Sonia Alejandra Augustsson, Carita Jenchen, Uwe Barboza Gudiño, José Rafael Alemán Gallardo, Eduardo Alejandro Ramírez Fernández, Juan Alonso Torres Sánchez, Darío Abratis, Michael Petrology and geochemistry of meta-ultramafic rocks in the Paleozoic Granjeno Schist, northeastern Mexico: Remnants of Pangaea ocean floor |
| thumbnail | https://rediab.uanl.mx/themes/sandal5/images/online.png |
| title | Petrology and geochemistry of meta-ultramafic rocks in the Paleozoic Granjeno Schist, northeastern Mexico: Remnants of Pangaea ocean floor |
| title_full | Petrology and geochemistry of meta-ultramafic rocks in the Paleozoic Granjeno Schist, northeastern Mexico: Remnants of Pangaea ocean floor |
| title_fullStr | Petrology and geochemistry of meta-ultramafic rocks in the Paleozoic Granjeno Schist, northeastern Mexico: Remnants of Pangaea ocean floor |
| title_full_unstemmed | Petrology and geochemistry of meta-ultramafic rocks in the Paleozoic Granjeno Schist, northeastern Mexico: Remnants of Pangaea ocean floor |
| title_short | Petrology and geochemistry of meta-ultramafic rocks in the Paleozoic Granjeno Schist, northeastern Mexico: Remnants of Pangaea ocean floor |
| title_sort | petrology and geochemistry of meta ultramafic rocks in the paleozoic granjeno schist northeastern mexico remnants of pangaea ocean floor |
| topic | SD Ciencia forestal |
| url | http://eprints.uanl.mx/18249/1/540.pdf |
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