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

Abstract

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.

Geological Sheet Tehuacán 14Q-i-(10), Puebla and Oaxaca states, southern Mexico

“…The proposed stratigraphy is summarized in Figure 2a, b and c, and combines the results of previous studies and new observations made in this work (e.g. Calderón-García, 1956;Centeno-García, Mendoza-Rosales, & Silva-Romo, 2009;Elías-Herrera & Ortega-Gutiérrez, 2002;Helbig, Keppie, Murphy, & Solari, 2012;Hernández-Láscares, 2000;Kirsch, Keppie, Murphy, & Solari, 2012;Martini et al, 2016;Mendoza-Rosales, 2010;Morán-Zenteno, Caballero-Miranda, Silva-Romo, Ortega-Guerrero, & González-Torres, 1993;Ortega-Gutiérrez, 1978a;Pérez-Ibargüengoitia, Hokuto-Castillo, & De Cserna, 1965; Silva-Romo, Mendoza-Rosales, Campos-Madrigal, Morales Yáñez, et al, 2018;Verde-Ramírez, 2015). The Main Map provides key constraints for future geological research, since it represents units and geological features still debated by researchers.…”

“…According to Martini et al (2016), generally, the Piedra Hueca Formation consists of fining-upwards successions that begin with conglomerates. The conglomerates are composed of foliated quartzofeldespathic rock clasts, sandstone and shale.…”

Mesozoic exhumation history of the Grenvillian Oaxacan Complex, southern Mexico

“…For instance, Oaxaquia (including the OC) was an important source terrane for voluminous submarine fans formed along the western margin of Pangea during the Late Triassic (Tolimán fan, Potosí fan; Barboza‐Gudiño et al., 2010; Centeno‐García, 2005; Ortega‐Flores et al., 2014, 2016). Clastic materials of the Early to Middle Jurassic Piedra Hueca and the Middle Jurassic Otlaltepec Formations, which crop out within the Otlaltepec Basin (the northern Mixteco terrane; Figure 2), were partly derived from the OC (Martini et al., 2016). Late Triassic (?)…”

“…Numerous provenance studies performed in Mesozoic clastic units of Mexico were primarily based on single‐grain detrital zircon U–Pb geochronology (e.g. Barboza‐Gudiño, Zavala‐Monsiváis, Venegas‐Rodríguez, & Barajas‐Nigoche, 2010; Martini et al., 2016; Mendoza‐Rosales, Centeno‐García, Silva‐Romo, Campos‐Madrigal, & Bernal, 2010; Ortega‐Flores, Solari, & Escalon‐Alcázar, 2016; Ortega‐Flores, Solari, Lawton, & Ortega‐Obregón, 2014; Pérez‐Gutiérrez, Solari, Gómez‐Tuena, & Valencia, 2009; Sierra‐Rojas et al, 2020; Zepeda‐Martínez, Martini, & Solari, 2018), a radiometric technique that can actually be classified as a conventional tool for provenance analyses. The technique is undoubtedly useful to obtain quite reliable provenance signals from ancient and recent sediments.…”

The ferns in a new Middle Jurassic locality from the Otlaltepec Formation, Puebla, Mexico

“…The plant fossils are found in the Otlaltepec Formation, which is composed of an alternation of lithofacies including conglomerates, palaeosols, horizontally interlaminated mudstones, siltstones and very fine-grained sandstones, and fine to very coarse-grained sandstone displaying trough cross-bedding (Fig. 2; Martini et al 2016). Detailed information on the lithostratigraphic section is given in Martini et al (2016).…”