Provenance of Ordovician clastic sequences of the San Rafael Block (Central Argentina), with emphasis on the Ponón Trehué Formation

Accretion of Grenvillian terranes to the southwestern border of the Río de la Plata craton, western Argentina

“…Recent detrital zircon study from the Ponon Trehue Formation has identified almost only Mesoproterozoic ages narrowly peaked around 1,213 Ma, implying a local, restricted provenance from the Grenvillian basement (Abre et al 2010), in agreement with the proposed sedimentation model within an extensional regime ruled by tectonic instability (Astini 2002;Heredia 2006). The detrital zircon ages are also consistent with the U-Pb crystallization age of *1,215 Ma mentioned for the basement.…”

APMdisc: An online computer program for the geochemical discrimination of siliciclastic sediments from active and passive margins

“…Similarly, 7 samples plotted in the passive margin field of the major and trace element-based diagram (Figure 6a). Therefore, a passive margin setting could be inferred for the Ordovician samples compiled from Abre et al (2011), with mean probability values of 0.955 and 0.953, respectively, for M and MT diagrams - Figure 4. One-axis discriminant function DF ilr(A-P)MT diagram for the subdivision of Active (A) and Passive (P) margins (Table AI-12) based on isometric (i) log-ratio transformation of system based on combined major and trace elements (MT), shows test studies TS1-TS9 (Table 2) ( Table 3).…”

“…Similarly, 7 samples plotted in the passive margin field of the major and trace element-based diagram (Figure 6a). Therefore, a passive margin setting could be inferred for the Ordovician samples compiled from Abre et al (2011), with mean probability values of 0.955 and 0.953, respectively, for M and MT diagrams (Table 3). The original authors (Abre et al, 2011) proposed an extensional tectonic setting for their study area, which was based on geological considerations.…”

“…One-axis discriminant function DF ilr(A-P)MT diagram for the subdivision of Active (A) and Passive (P) margins (Table AI-12) based on isometric (i) log-ratio transformation of system based on combined major and trace elements (MT), shows test studies TS1-TS9 (Table 2) ( Table 3). The original authors (Abre et al, 2011) proposed an extensional tectonic setting for their study area, which was based on geological considerations. Our inference of a passive margin is consistent with their proposal.…”

“…Our first application study is from Abre et al (2011), who reported geochemical data for 8 Ordovician sandstone and mudstone samples from Argentina. All 8 samples plotted within the passive margin field in the major element-based diagram (Figure 5a).…”