Petrographycal aspects of jurassic volcanic deposits of the Peruvian south coast are analyzed in the present work, which correspond to andesites and basalts corresponding to the Chocolate Formation and Chert stratified facies of the Guaneros Formation, the volcanic ones belong to a system of volcanic arc whereas deposits of the Guaneros Formation are signal of a cortical thinning for this period in the Peruvian South margin.

Petrographycal aspects of jurassic volcanic deposits of the Peruvian south coast are analyzed in the present work, which correspond to andesites and basalts corresponding to the Chocolate Formation and Chert stratified facies of the Guaneros Formation, the volcanic ones belong to a system of volcanic arc whereas deposits of the Guaneros Formation are signal of a cortical thinning for this period in the Peruvian South margin.

The Mesozoic rocks of southern Peru comprise a Middle Jurassic to Early Cretaceous sedimentary sequence deposited during a time interval of approximately 34 Myr. In Tacna, these rocks are detrital and constitute the Yura Group (Callovian to Tithonian) and the Hualhuani Formation (Berriasian). Basing on robust interpretation of facies and petrographic analysis, we reconstruct the depositional settings of such units and provide a refined stratigraphic framework. Accordingly, nine types of sedimentary facies and six architectural elements are defined. They preserve the record of a progradational fluvial system, in which two styless regulated the dispersion of sediments: (i) a high-to moderate-sinuosity meandering setting (Yura Group), and a later (ii) incipient braided setting (Hualhuani Formation).The Yura Group (Callovian-Tithonian) represents the onset of floodplain deposits and lateral ...

The Camaná-Mollendo Basin is an active-margin depression ~NW-SE elongated, which is located in the forearc of southern Perú and extends from the Coastal Cordillera to the Perú-Chile Trench. This basin consists of a grabens and half-graben complex, filled with deltaic and fluvial sedimentary rocks of the Oligocene-Pliocene Camaná Formation (~500 m thick). An integration of compiled onshore stratigraphic logs, reinterpreted 2D seismic offshore information, sediment provenance data, and previous zircon U-Pb geochronology on volcanic reworked ash supports a refined tectono-chronostratigraphic framework for the whole Camaná-Mollendo Basin fill. To complete this integration we needed firstly to elaborate a geological reinterpretation of seismic offshore data and highlight their most prominent features (i.e., erosive surfaces). This step allowed establishing a first correlation between ons...