Exotic rifted passive margin of a back-arc basin off western Pangea: geochemical evidence from the Early Mesozoic Ayú Complex, southern Mexico

Helbig, Maria; Keppie, J. Duncan; Murphy, J. Brendan; Solari, Luigi Augusto

doi:10.1080/00206814.2012.751171

Cited by 19 publications

(13 citation statements)

References 80 publications

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“…This hypothesis is consistent with the calc-alkaline geochemistry and arc signature of granitoids in the Acatlán Complex which intruded between ~488 Ma and ~442 Ma (e.g. Miller et al, 2007;Keppie et al, 2010Keppie et al, , 2012a (Fig. 17).…”

Section: Tectonic Modelsupporting

confidence: 69%

“…17) or northwestward from the basement rocks of the Santander Massif and the Mérida Andes during the Palaeozoic (e.g. Helbig et al, 2012a;Keppie and Keppie, 2012). A potential position for the Acatlán Complex prior to its separation from Gondwana may be outboard of the Triassic magmatic belt in Ecuador and southerncentral Colombia (Fig.…”

Section: Tectonic Modelmentioning

confidence: 98%

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Palaeozoic to Early Jurassic history of the northwestern corner of Gondwana, and implications for the evolution of the Iapetus, Rheic and Pacific Oceans

et al. 2016

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The Palaeozoic to Mesozoic igneous and metamorphic basement rocks exposed in the Mérida Andes of Venezuela and the Santander Massif of Colombia are generally considered to define allochthonous terranes that accreted to the margin of Gondwana during the Ordovician and the Carboniferous. However, terrane sutures have not been identified and there are no published isotopic data that support the existence of separate crustal domains. A general paucity of geochronological data led to published tectonic reconstructions for the evolution of the north- western corner of Gondwana that do not account for the magmatic and metamorphic histories of the basement rocks of the Mérida Andes and the Santander Massif. We present new zircon U–Pb (ICP-MS) data from 52 igneous and metamorphic rocks, which we combine with whole rock geochemical and Pb isotopic data to constrain the tectonic history of the Precambrian to Mesozoic basement of the Mérida Andes and the Santander Massif. These data show that the basement rocks of these massifs are autochthonous to Gondwana and share a similar tectono- magmatic history with the Gondwanan margin of Peru, Chile and Argentina, which evolved during the subduc- tion of oceanic lithosphere of the Iapetus Ocean. The oldest Palaeozoic arc magmatism is recorded at ~500 Ma, and was followed shortly by Barrovian metamorphism. Peak metamorphic conditions at upper amphibolite facies are recorded by anatexis at ~477 Ma and the intrusion of synkinematic granitoids until ~472 Ma. Subsequent retrogression resulted from localised back-arc or intra-arc extension at ~453 Ma, when volcanic tuffs and interfingered sedimentary rocks were deposited over the amphibolite facies basement. Continental arc magmatism dwindled after ~430 Ma and terminated at ~415 Ma, coevally with most of the western margin of Gondwana. After Pangaea amalgamation in the Late Carboniferous to Early Permian, a magmatic arc developed on its western margin at ~ 294 Ma as a result of subduction of oceanic crust of the palaeo-Pacific ocean. Intermittent arc magmatism recorded between ~ 294 and ~ 225 Ma was followed by the onset of the Andean subduction cycle at ~ 213 Ma, in an extensional regime. Extension was accompanied by slab roll-back which led to the migration of the arc axis into the Central Cordillera of Colombia in the Early Jurassic

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Section: Tectonic Modelsupporting

confidence: 69%

Section: Tectonic Modelmentioning

confidence: 98%

Palaeozoic to Early Jurassic history of the northwestern corner of Gondwana, and implications for the evolution of the Iapetus, Rheic and Pacific Oceans

et al. 2016

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“…By the beginning of Mesozoic time, the Acatlán-Cuicatlán sector of southern Mexico was composed of a mosaic of distinct metamorphic and plutonic assemblages that are grouped into the Oaxacan Complex ( Fig. 2; Ortega-Gutiérrez, 1981), Acatlán Complex (Ortega-Gutiérrez, 1981;Keppie et al, 2008a), Ayú Complex (Helbig et al, 2012), and the East Mexico Arc (Dickinson and Lawton, 2001). The crustal attenuation associated with breakup of Pangea produced a number of Jurassic, extensional to transtensional basins, including the Otlaltepec Basin (Fig.…”

Section: Geological Backgroundmentioning

confidence: 99%

Provenance analysis of Jurassic sandstones from the Otlaltepec Basin, southern Mexico: Implications for the reconstruction of Pangea breakup

et al. 2016

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The structural evolution that accompanied the breakup of Pangea during Jurassic time has been constrained in Mexico only at the regional scale on the basis of global plate tectonics and geometric considerations. According to available regional-scale reconstructions, the Jurassic tectonic evolution of Mexico was characterized by: (1) anticlockwise rotation of the Yucatán block along NNW-trending dextral faults and (2) sinistral block motions along W-to WNW-trending faults, which are geometrically needed to restore southern and central Mexico to the northwest of its present position during early Mesozoic time and avoid the overlap between North and South America in the reconstruction of Pangea. Reports of W-to WNW-trending sinistral faults that were active in Mexico during Jurassic time are presently few, and the existence, extension, and age of some of these structures have been questioned by many authors. In this work, we present the provenance analysis from a Jurassic clastic succession deposited within the Otlaltepec Basin in southern Mexico. Wholerock sandstone petrography integrated with chemical analysis of detritalgarnet and U-Pb detrital-zircon geochronology documents that the analyzed stratigraphic record was deposited during rapid exhumation of the Totoltepec pluton along the Matanza fault, which is a W-trending sinistral normal fault that extends along the southern boundary of the Otlaltepec Basin. U-Pb zircon ages and biostratigraphic data bracket the age of the Matanza fault between 163.5 ± 1 and 167.5 ± 4 Ma. This indicates that the Matanza fault was involved in the crustal attenuation that accompanied the breakup of Pangea and that sinistral motion of continental blocks along W-trending structures was taking place in southern Mexico as predicted by global plate tectonic reconstructions.

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“…Muscovite (PET-719-2) was separated from a mylonite in the Providencia shear zone, which is a large, NE-dipping shear zone with thrust on August 3, 2015 lithosphere.gsapubs.org Downloaded from kinematics containing various tectonic fragments of different units, and juxtaposing metasedimentary rocks of the Chazumba Lithodeme against rocks of the Cosoltepec Formation (Helbig et al, 2012a(Helbig et al, , 2012b. The 40 Ar/ 39 Ar age spectrum is partly disturbed ( Fig.…”

Section: Results and Interpretationmentioning

confidence: 99%

“…1A). The Middle-Late Triassic of central and southern Mexico marked the development of a passive or rifted margin along the western margin of Oaxaquia, associated with a thick succession of turbiditic siliciclastic rocks deposited in a submarine fan environment (Centeno-García, 2005;Centeno-García et al, 2008;Martini et al, 2009;Helbig et al, 2012aHelbig et al, , 2012b, before subductionrelated igneous activity was re-established by the Early Jurassic ( Fig. 1A; Bartolini et al, 2003).…”

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confidence: 99%

A Late Triassic tectonothermal event in the eastern Acatlán Complex, southern Mexico, synchronous with a magmatic arc hiatus: The result of flat-slab subduction?

et al. 2014

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Exotic rifted passive margin of a back-arc basin off western Pangea: geochemical evidence from the Early Mesozoic Ayú Complex, southern Mexico

Cited by 19 publications

References 80 publications

Palaeozoic to Early Jurassic history of the northwestern corner of Gondwana, and implications for the evolution of the Iapetus, Rheic and Pacific Oceans

Palaeozoic to Early Jurassic history of the northwestern corner of Gondwana, and implications for the evolution of the Iapetus, Rheic and Pacific Oceans

Provenance analysis of Jurassic sandstones from the Otlaltepec Basin, southern Mexico: Implications for the reconstruction of Pangea breakup

A Late Triassic tectonothermal event in the eastern Acatlán Complex, southern Mexico, synchronous with a magmatic arc hiatus: The result of flat-slab subduction?

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