气候变化领域集成服务门户(CCPortal): Multi-stage, Upper Eocene-Oligocene anatexis in the Xolapa metamorphic belt (Puerto Escondido, Mexico): Dynamics of the Xolapa Complex as the decoupled lower crust of the Chortís Block upper crust during its tectonic migration

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DOI	10.1016/j.tecto.2021.229004
	Multi-stage, Upper Eocene-Oligocene anatexis in the Xolapa metamorphic belt (Puerto Escondido, Mexico): Dynamics of the Xolapa Complex as the decoupled lower crust of the Chortís Block upper crust during its tectonic migration
	Peña-Alonso T.A.; Latorre C.; Estrada-Carmona J.; Molina-Garza R.S.; Solari L.
发表日期	2021
ISSN	00401951
卷号	815
英文摘要	Three successive strain regimes spanning up to ~16 million years were identified from the field, structural and geochronological analyses in Upper Eocene-Oligocene migmatites of the Xolapa Complex around the Puerto Escondido longitude (~97°W), in southern Mexico. A west-facing asymmetric folding affecting diatexites at ca. 38–31 Mad defines Regime A. Regimes B and C affected younger metatexites. Regime B recorded an outward extension at ca. 31–25 Ma, whereas Regime C occurred at ca. 25–22 Ma as NE-directed thrusting. By coupling the Upper Cretaceous-Oligocene tectonic framework of southern Mexico with the dynamics and timing of the identified strain regimes, we interpret that Regimes A to C recorded distinct stages of the separation and eastward migration of the Chortís Block, viewed as a continuous geodynamic episode. According to our proposal, the upper and lower crust of Chortís adjacent to nuclear Mexico were vertically decoupled before its separation by the presence of pre-Eocene crustal anisotropies. Regime A occurred when the Chortís Block rode over the Xolapa Complex during its initial eastward escape. Since this episode, the Chortís Block (upper crust) was captured by the Caribbean plate, whereas the Xolapa Complex (lower crust) remained as the southernmost North America plate. Chortís eastward migration and the consequent unloading of its decoupled lower crust triggered anatexis, isostatic adjustments, and diachronous uplift of the Xolapa Complex (Regime B). The progressive substitution of Chortís by its thinner lower crust in the tectonic configuration next to nuclear Mexico gradually enhanced the local convergence rate between the Farallon/Cocos plate and just-severed North America. The Farallon/Cocos plate was accreted to North America (Regime C) after a critical lengthening of the uprising lower crust along the southern Mexican margin. The local increase of the convergence rate promoted the landward consumption of the Xolapa Complex by subduction erosion since 22 Ma. © 2021 Elsevier B.V.
关键词	Chortís Block migration Coastal Plutonic Belt Farallon/Cocos plate Migmatites Southern Mexico Xolapa Complex
英文关键词	Geochronology; Plates (structural components); Tectonics; Unloading; Convergence rates; Crustal anisotropy; Local Convergence; Metamorphic belts; Subduction erosion; Tectonic framework; Upper Cretaceous; Upper Eocene; Geodynamics
语种	英语
来源期刊	Tectonophysics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/208051
作者单位	Facultad de Ingeniería, Universidad Autónoma de Tamaulipas, Centro Universitario Tampico-Madero, Tampico, Tamaulipas 89339, Mexico; Departamento de Geociencias Aplicadas, Instituto Potosino de Investigación Científica y Tecnológica, Camino a la Presa San José No. 2055. Col. Lomas 4ª Sección, San Luis Potosí, S.L.P., 78216, Mexico; Centro de Geociencias, Universidad Nacional Autónoma de México, Blvd. Juriquilla No. 3001, Querétaro, Juriquilla 76230, Mexico
推荐引用方式 GB/T 7714	Peña-Alonso T.A.,Latorre C.,Estrada-Carmona J.,et al. Multi-stage, Upper Eocene-Oligocene anatexis in the Xolapa metamorphic belt (Puerto Escondido, Mexico): Dynamics of the Xolapa Complex as the decoupled lower crust of the Chortís Block upper crust during its tectonic migration[J],2021,815.
APA	Peña-Alonso T.A.,Latorre C.,Estrada-Carmona J.,Molina-Garza R.S.,&Solari L..(2021).Multi-stage, Upper Eocene-Oligocene anatexis in the Xolapa metamorphic belt (Puerto Escondido, Mexico): Dynamics of the Xolapa Complex as the decoupled lower crust of the Chortís Block upper crust during its tectonic migration.Tectonophysics,815.
MLA	Peña-Alonso T.A.,et al."Multi-stage, Upper Eocene-Oligocene anatexis in the Xolapa metamorphic belt (Puerto Escondido, Mexico): Dynamics of the Xolapa Complex as the decoupled lower crust of the Chortís Block upper crust during its tectonic migration".Tectonophysics 815(2021).