Guadalupian and Lopingian (Middle and Late Permian) deposits from Mexico and Guatemala, a review with new data

Permian-Carboniferous arc magmatism and basin evolution along the western margin of Pangea: Geochemical and geochronological evidence from the eastern Acatlan Complex, southern Mexico

“…Evidence of arc activity in southern Mexico (Figs. 2 and 14) may also be preserved in (1) the latest Pennsylvanian to Middle Permian Tecomate Formation type area, which contains mafi c fl ows, tuffs, and rare felsic units (Keppie et al, 2004b;Sánchez-Zavala, 2008), (2) the Middle Permian Los Hornos Formation (Ramírez et al, 2000;Vachard et al, 2004), and (3) the uppermost Devonian to Lower Permian Patlanoaya Group, which contains intercalations of bentonite horizons representing ash-fall deposits Vachard and de Dios, 2002). The un deformed Olinalá Formation of Middle to Upper Permian age (Buitrón et al, 2005) is potentially also partially correlative with the Chichihualtepec Tecomate Formation strata, although volcanic rocks have not been described in this unit.…”

Palaeozoic palaeogeography of Mexico: constraints from detrital zircon age data

“…The formation is floored by a massive conglomerate containing quartzite and schist detritus, and includes fossiliferous black shales, estuarine sandstones and locally stromatolitic limestones that have been dated as middle Permian on the basis of ammonoids, brachiopods and fusilinids (González-Arreola et al 1994;Vachard et al 2004).…”

Algunos crinoides (Echinodermata-Crinoidea) del Pérmico de la región de Pemuxco, Hidalgo

“…El contacto superior de la Formación Tuzancoa es discordante con los lechos rojos de la Formación Huizachal, tal como se observa en los cortes de la terracería de Jalapa, Hidalgo (Hoja Zacualtipán, INEGI, 2001 Arellano et al, 1998;Vachard et al, 2004;Buitrón et al, 2008) que precisa la edad del Pérmico temprano (Leonardiano) para toda la asociación fósil. Además, se hallaron fragmentos de briozoarios fenestélidos y braquiópodos espiriféridos.…”