Neogene erosion of the Andean Cordillera in the flat-slab segment as indicated by petrography and whole-rock geochemistry from the Manantiales Foreland Basin (32°–32°30′S)

Andean Mountain Building and Foreland Basin Evolution During Thin‐ and Thick‐Skinned Neogene Deformation (32–33°S)

“…Paleocurrent measurements from this study (supporting information Table S1; eolian member) and Jordan et al (1996; upper member) show generally east and southeast directed sediment transport throughout the Manantiales section (Figure 3), and previous studies have linked facies and provenance trends to thrust activity in the Principal and Frontal Cordilleras (Cristallini & Ramos, 2000; Jordan et al, 1996; Perez, 1995; Pinto et al, 2018). This study builds upon numerous investigations and data sets (e.g., clast counts, sandstone petrography, volcanic and sandstone geochemistry, heavy mineral analyses, zircon fission track and U‐Pb geochronology, magnetostratigraphy, paleontology, and paleoaltimetry) that address the timing and nature of Manantiales Basin accumulation (Figure 3; Alarcón & Pinto, 2015; Hoke et al, 2014; Iglesia Llanos, 1995; Jordan et al, 1996; López et al, 2011; Perez, 1995; Pérez, 2001; Pinto et al, 2018; Ruskin et al, 2011).…”

High-resolution compositional analysis of a fluvial-fan succession: The Miocene infill of the Cacheuta Basin (central Argentinian foreland)

“…This Ca-rich signature is most likely related to input from the Mesozoic sedimentary units within the eastern Principal Cordillera (Fig. 1A; Cegarra and Ramos, 1996;Cristallini and Ramos, 2000;Alarcon and Pinto, 2015), confirmed by the petrographic data reported by Irigoyen (1997) and by analogy with the sedimentary infill of the coeval Alto Tunuyán Basin which comprises clasts originating from the Mesozoic sedimentary units (Giambiagi and Ramos, 2003).…”

“…The weathering history of the sandstones can be evaluated using the Chemical Index of Alteration (CIA; Nesbitt and Young, 1982). This tool has proved to be useful in examining compositional variations of mudstones as well as sandstones, due to changes in the intensity of weathering in the source area (e.g., Fedo et al, 1995;Price and Velbel, 2003;Goldberg and Humayun, 2010;Shao and Yang, 2012;Alarcon and Pinto, 2015;Nagarajan et al, 2015;Zaid et al, 2015;Garzanti and Resentini, 2016). This index can be calculated using molecular proportions of major element oxides (Eq.…”

“…3) and are part of early diagenesis during initial burial of the sediments (Burley and Worden, 2003;Steel and Milliken, 2013). Their presence obscures information that might give insights on factors taking place at different temporal and spatial scales (Alarcon and Pinto, 2015). Hence, in order to avoid spurious compositional signals related to the presence of these secondary minerals, PCA calculations were performed on CaO-, calcite-and zeolite-free data.…”

“…The classical diagram for discrimination of igneous suites by Le Maitre et al (1989) has been applied to the sedimentary rocks ( Nb/Y of Winchester and Floyd (1977) has also been used to infer source rock composition from the ACCEPTED MANUSCRIPT Fig. 14;Fralick 2003;Pinto et al, 2004;Alarcon and Pinto, 2015). It relies on immobile elements while neglecting the SiO 2 and alkali content of the rocks.…”