Mid-Tertiary cooling ages in the Precambrian Oaxacan Complex of southern Mexico: indication of exhumation and inland arc migration
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| Formato: | Artículo científico |
| Lenguaje: | en |
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Universidad Nacional Autónoma de México
2004
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| _version_ | 1876470500125835264 |
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| author | Amabel Ortega Rivera |
| author_facet | Amabel Ortega Rivera |
| contents | Mid-Tertiary cooling ages in the Precambrian Oaxacan Complex of southern Mexico: indication of exhumation and inland arc migration Amabel Ortega Rivera Carlos Heinrich Schulze James K. W. Lee John Duncan Keppie Fernando Ortega Gutiérrez Ciencias de la Tierra Tertiary Precambrian cooling ages arc magmatism Oaxacan Complex In southern Mexico, the ~1 Ga Oaxacan Complex is in fault contact with the MesozoicCenozoicChatino terrane. 40Ar/39Ar dating of minerals from hornblende gneiss and quartz monzonitic gneiss inthe southern Oaxacan Complex collected, 10 km and 1 km north of the OaxacaXolapa boundary,yielded the following data, respectively: (1) a plateau age of 584 ± 10 Ma in hornblende and apseudoplateau age of 23 ± 3 Ma in biotite; and (2) a plateau age of 42 ± 3 Ma in biotite, and a maximumage of 36 ± 1 Ma in K-feldspar. These are inferred to date cooling through ~500550° C for hornblende,~280° C for biotite, ~220° C for plagioclase, and ~310270° C for K-feldspar. The ~582 Ma age is muchyounger than cooling ages from the northern Oaxacan Complex, suggesting that it records resettingduring a Neoproterozoic Brasiliano tectonothermal event. On the other hand, the Tertiary cooling agessuggest reheating adjacent to either ~40 Ma or 3525 Ma Tertiary plutons: ~42 Ma and ~23 Ma biotiteages, respectively. The former was followed by rapid cooling through ~310270° C by ~36 Ma andexhumation before deposition of Miocene volcanic rocks. We relate these cooling ages to northwardmigration of the magmatic arc during the OligoceneMiocene as a consequence of flattening of thesubduction zone due to subduction erosion. 2004 artículo científico 1026-8774 https://www.redalyc.org/articulo.oa?id=57221201 en http://www.redalyc.org/revista.oa?id=572 Revista Mexicana de Ciencias Geológicas application/pdf Universidad Nacional Autónoma de México Revista Mexicana de Ciencias Geológicas (México) Num.2 Vol.21 |
| format | Artículo científico |
| id | redalyc_57221201 |
| institution | Redalyc |
| language | en |
| publishDate | 2004 |
| publisher | Universidad Nacional Autónoma de México |
| spellingShingle | Mid-Tertiary cooling ages in the Precambrian Oaxacan Complex of southern Mexico: indication of exhumation and inland arc migration Amabel Ortega Rivera Ciencias de la Tierra Tertiary Precambrian cooling ages arc magmatism Oaxacan Complex Mid-Tertiary cooling ages in the Precambrian Oaxacan Complex of southern Mexico: indication of exhumation and inland arc migration Amabel Ortega Rivera Carlos Heinrich Schulze James K. W. Lee John Duncan Keppie Fernando Ortega Gutiérrez Ciencias de la Tierra Tertiary Precambrian cooling ages arc magmatism Oaxacan Complex In southern Mexico, the ~1 Ga Oaxacan Complex is in fault contact with the MesozoicCenozoicChatino terrane. 40Ar/39Ar dating of minerals from hornblende gneiss and quartz monzonitic gneiss inthe southern Oaxacan Complex collected, 10 km and 1 km north of the OaxacaXolapa boundary,yielded the following data, respectively: (1) a plateau age of 584 ± 10 Ma in hornblende and apseudoplateau age of 23 ± 3 Ma in biotite; and (2) a plateau age of 42 ± 3 Ma in biotite, and a maximumage of 36 ± 1 Ma in K-feldspar. These are inferred to date cooling through ~500550° C for hornblende,~280° C for biotite, ~220° C for plagioclase, and ~310270° C for K-feldspar. The ~582 Ma age is muchyounger than cooling ages from the northern Oaxacan Complex, suggesting that it records resettingduring a Neoproterozoic Brasiliano tectonothermal event. On the other hand, the Tertiary cooling agessuggest reheating adjacent to either ~40 Ma or 3525 Ma Tertiary plutons: ~42 Ma and ~23 Ma biotiteages, respectively. The former was followed by rapid cooling through ~310270° C by ~36 Ma andexhumation before deposition of Miocene volcanic rocks. We relate these cooling ages to northwardmigration of the magmatic arc during the OligoceneMiocene as a consequence of flattening of thesubduction zone due to subduction erosion. 2004 artículo científico 1026-8774 https://www.redalyc.org/articulo.oa?id=57221201 en http://www.redalyc.org/revista.oa?id=572 Revista Mexicana de Ciencias Geológicas application/pdf Universidad Nacional Autónoma de México Revista Mexicana de Ciencias Geológicas (México) Num.2 Vol.21 |
| title | Mid-Tertiary cooling ages in the Precambrian Oaxacan Complex of southern Mexico: indication of exhumation and inland arc migration |
| topic | Ciencias de la Tierra Tertiary Precambrian cooling ages arc magmatism Oaxacan Complex |
| url | https://www.redalyc.org/articulo.oa?id=57221201 |