Reply to Molina-Garza et al. (2019) 'Discussion of: Ortega-Flores et al. (2018) provenance analysis of Oligocene sandstone from the Cerro Pelon area, southern Gulf of Mexico'

摘要

The origin of the Oligocene turbidites from the Cerro Pelon area in south Gulf Mexico proposed by Ortega-Flores ef al. (2018) is in disagree with the interpretations made by Molina-Garza ef al. (2019), which main criticism is based on U-Pb ages of detrital zircons from the matrix of a conglomerate unit, which they refer to as 'Nanchital Conglomerate', as well as on the presence of limestone, gabbros, and mafic protolith-derived clasts. Molina-Garza et al. (2019) basically interpret the Nanchital Conglomerate as Miocene in age, which was sourced mainly from metamorphic complexes including their sedimentary covers located to the west and south of the Cerro Pelon area. For some reason, Molina-Garza et al. (2019) suppose that the Nanchital Conglomerate should have the same provenance sources that the Oligocene turbidites from Cerro Pelon area, reported by Ortega-Flores et al. (2018). Based on the foregoing, we strongly disagree with Molina-Garza ef al. (2019) considering that, from the beginning, they intend to compare two units of different age. Additionally, the scarce data reported from both the matrix and the clasts of the Nanchital Conglomerate are not determinant for interpreting the provenance of this conglomeratic unit and subsequently, to consider the same rock sources from the Oligocene through Miocene time.