Browsing by Author "Mariño, Jersy"
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Item Restricted In situ cosmogenic 3He and 36Cl and radiocarbon dating of volcanic deposits refine the Pleistocene and Holocene eruption chronology of SW Peru(Springer, 2019-11-07) Bromley, Gordon R. M.; Thouret, Jean-Claude; Schimmelpfennig, Irene; Mariño, Jersy; Valdivia, David; Rademaker, Kurt; Vivanco López, Socorro del Pilar; ASTER Team; Aumaître, Georges; Bourlès, Didier; Keddadouche, KarimConstraining the age of young lavas, which generally fall outside the effective range of traditional geochronology methods, remains a key challenge in volcanology, limiting the development of high-resolution eruption chronologies. We present an in situ cosmogenic ³He and ³⁶Cl surface-exposure chronology, alongside new minimum-limiting ¹⁴C ages, documenting young eruptions at five sites in the Western Cordillera, southern Peru. Four ³He-dated lavas on the Nevado Coropuna volcanic complex (hitherto thought to be dormant) indicate that the central dome cluster is young and potentially active; two Holocene lavas on the easternmost dome are the youngest directly dated lavas in Peru to date. East of Coropuna, lava domes and block-lava flows represent the most extensive output to date of Nevado Sabancaya, one of Peru’s most active volcanoes. Two ³He measurements confirm the Holocene age of these deposits and expand the chronology for one of the youngest major lava fields in Peru. ³⁶Cl surface-exposure ages from the Purupurini dome cluster and Nevado Casiri document middle-late-Holocene episodes of effusive activity, while basal ¹⁴C ages from a lavadammed wetland constrain an effusive eruption at Mina Arcata, north of Coropuna, to the late-glacial period. These new data advance the recent Western Cordillera volcanic record whilst demonstrating both the considerable potential and fundamental limitations of cosmogenic surface-exposure methods for such applications.Item Restricted Multidisciplinary study of the impacts of the 1600 CE Huaynaputina eruption and a project for geosites and geo-touristic attractions(Springer, 2021-07) Mariño, Jersy; Cueva, Kevin; Thouret, Jean-Claude; Arias, Carla; Finizola, Antony; Antoine, Raphael; Delcher, Eric; Fauchard, Cyrille; Donnadieu, Franck; Labazuy, Philippe; Japura, Saida; Gusset, Rachel; Sanchez, Paola; Ramos, Domingo; Macedo Franco, Luisa Diomira; Lazarte, Ivonne; Liliane, Thouret; Del Carpio Calienes, José Alberto; Jaime, Lourdes; Saintenoy, ThibaultThe Huaynaputina volcano, southern Peru, was the site of the largest historical eruption (VEI 6) in the Andes in 1600 CE, which occurred during the historic transition between the Inca Empire and the Viceroyalty of Peru. This event had severe consequences in the Central Andes and a global climatic impact. Spanish chronicles reported that at least 15 villages or settlements existed around the volcano, of which seven of them were totally destroyed by the eruption. Multidisciplinary studies have allowed us to identify and analyze the characteristics of six settlements buried by the eruption. Tephra fallout and pyroclastic current deposits (PDCs) had different impacts according to the settlement distance from the crater, the location with respect to the emplacement of PDCs along valleys, the geomorphological characteristics of the site, and type of constructions. Thus, Calicanto, Cojraque, and San Juan de Dios, located beneath the main axis of tephra dispersal lobe due west and/or on valley edges, were buried under several meters of pyroclastic deposits, while the villages of Estagagache, Chimpapampa, and Moro Moro, located to the S and SE of the lobe, were partially mantled by tephra. The 1600 CE Huaynaputina eruption created an important geological and cultural heritage, which has scientific, educational, and touristic values. Geo-touristic attractions are proposed based on identification, characterization, and qualitative evaluation of four groups totaling 17 geosites: volcanic geosites, volcanic-cultural geomorphosites, and hot springs. Seven geological roads along with seven viewpoints are proposed, which allow to value the most relevant landscapes, deposits and geological structures.Item Restricted Petrological and geochemical constraints on the magmatic evolution at the Ampato-Sabancaya compound volcano (Peru)(Elsevier, 2023-09-23) Rivera, Marco; Samaniego, Pablo; Nauret, François; Mariño, Jersy; Liorzou, CélineIn order to gain insights into continental arc magmatic processes, we have conducted a petrological and geochemical study of major and trace elements and Sr, Nd, and Pb isotopes of the Ampato-Sabancaya compound volcano, which belongs to the Andean Central Volcanic Zone (CVZ). Whole-rock compositions for Ampato and Sabancaya range from andesites to dacites (56.7–69.3 wt% SiO2) and both belong to a medium- to high-K calk-alkaline magmatic series. Ampato-Sabancaya samples are characterized by high contents of large-ion lithophile elements (LILE; e.g., K, Rb, Ba, Th), low concentrations of high field strength elements (HFSE; e.g., Nb, Zr) and heavy rare earth elements (HREE; e.g., Yb), with consequently high La/Yb and Sr/Y ratios. An increase in these ratios is usually interpreted as a result of magmatic differentiation in the presence of garnet in the deep crust. A detailed analysis reveals that the rocks of Ampato-Sabancaya display three different compositional groups. (1) The first, composed mainly of andesites (56.7–59.8 wt% SiO2), corresponds to lavas from the early stage of the Ampato Basal edifice, as well as pyroclastic deposits from the Ampato Upper edifice. (2) The second group corresponds to andesitic and dacitic compositions (60.0–67.3 wt% SiO2) from the Ampato Basal edifice (Moldepampa stage), the Ampato Upper edifice, and the Sabancaya edifice. (3) The third group corresponds to dacitic compositions (65.0–69.3 wt% SiO2) associated with the Corinta Plinian fallout and pyroclastic flow deposits from the Ampato Upper edifice. This last group of dacites, erupted during the Ampato Upper edifice stage, have drastically different compositions from the other groups with Sr/Y (<27) and Sm/Yb (<4.7) ratios lower than other lavas and lacking evidence of amphibole and/or garnet fractionation during their genesis. As a whole, Sr, Nd, Pd isotopic ratios suggest that mantle-derived magmas are significantly affected by assimilation processes during their evolution, due to the thick (65–70 km) continental crust beneath the CVZ in southern Peru. In summary, the magmatic evolution of group 1 and 2 can be explained by a two-step model in which primitive magmas evolved in the deep crust in the so-called melting-assimilation-storage-homogenization (MASH)-type reservoirs by assimilation-fractional crystallization (AFC) processes involving garnet and/or amphibole. Then, amphibole-dominated upper crustal AFC processes and magma mixing are responsible for the geochemical diversity of the main ASCV trend. In contrats, the group 3 dacites followed an upper crustal AFC process (without amphibole) from a different primitive magma, which did not suffer the high pressure, garnet-dominated AFC processes. This evolution highlights the complexities associated to magma genesis and differentiation at continental arcs contructed on a thick crust.