Geologic occurrence and recent eruptive materials of the Lautaro Volcano, Chilean Patagonia

Motoki, Akihisa; Orihashi, Yuji; Naranjo, José A.; Hirata, Daiji; Hosono, Takahiro; Cario, Felipe Dias; Anma, Ryo

doi:10.5575/geosoc.109.ix

Cited by 3 publications

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Because the volcano is covered with a thick ice layer and powerfully eroded by glacial processes, its volcanic structure is entirely unknown. Reports of several eruptions, 1897 and at least one in 1959 (Martinic, , González‐Ferrán, ) as well as the presence of tephra and ash deposits on the ice surface of Viedma and O'Higgins glaciers (Kilian, ; Motoki et al ., ) show that Lautaro Volcano is one of the most active stratovolcanoes in the AVZ (Orihashi et al ., ). Viedma Volcano was active during the Holocene (González‐Ferrán, ; Stern, ) (Fig. a).…”

Section: Seismotectonic Settingmentioning

confidence: 99%

Neotectonics and seismicity in southern Patagonia

2015

View full text Add to dashboard Cite

Research for evaluation of geologic hazards involving earthquakes and volcanic eruptions in southern Argentina seems to have historically received little attention. Nevertheless, the relatively small work done indicates a Neogene tectonic architecture in the area with capability of generating potential hazardous earthquakes in a growing population region. Seismicity and some morphotectonic evidences of Quaternary activity of the Magallanes-Fagnano left-lateral fault system in the transform boundary between South America and Scotia plates, are analysed in this paper. This fault system is considered to be an important seismogenic source, responsible for large earthquakes that have occurred in southern Argentina. Some examples from the South and Austral Andean Volcanic Zones are also examined in order to show recent volcanic activity which also generated crustal seismicity. Preliminary hazard estimation clearly shows the presence of both potentially active volcanic centres in southern Patagonia that may also trigger seismicity and the high probability for large crustal earthquake generation. Figure 2. (a) Google Earth image of the central section of the Magallanes-Fagnano (MF) Fault. Lainez and Irigoyen rivers cross the fault scarp. Negro Lake is an example of a pull-apart basin produced by an 'en-échelon' strike-slip motion; (b) Google Earth image of the area east of Fagnano Lake showing the location of scarps and the narrow valley of Turbio River at its mouth. This figure is available in colour online at wileyonlinelibrary.com/journal/gj. L. PERUCCA ET AL.Figure 3. (a) Aerial oblique view to the fault trace (photo taken by Schiavini); (b) Google Earth image of the central portion of MF fault showing wind gaps and truncated meanders; (c) truncated alluvial plain and meander and aligned forest. This figure is available in colour online at wileyonlinelibrary.com/journal/gj. L. PERUCCA ET AL.

show abstract

Section: Seismotectonic Settingmentioning

confidence: 99%

Neotectonics and seismicity in southern Patagonia

2015

View full text Add to dashboard Cite

show abstract

“…2), on February 28th, 2002 (Motoki et al, 2003). Field observations, petrologic and geochemical data from the volcano are herein reported.…”

mentioning

confidence: 99%

Geologic reconnaissance of Lautaro Volcano, Chilean Patagonia

Motoki¹,

Orihashi²,

Naranjo³

et al. 2010

andgeo

Self Cite

View full text Add to dashboard Cite

Lautaro is the volcano closest to the Chile Triple Junction in the Andean Austral Volcanic Zone. The volcanic edifice of 3,607 m a.s.l. stands out on the north-western part of the plateau of the South Patagonian Ice Field. The volcano basement is composed of low-grade meta-pelites that are cut by tabular intrusive bodies of hornblende-biotite granite. The volcano is almost completely covered by ice and the study was performed on volcanic detritus present in terminal moraines of the Lautaro Glacier and the tephra on the surface of the O'Higgins Glacier. The terminal moraines of Lautaro Glacier contain fragments of light grey dacite rich in plagioclase and hornblende phenocrysts. Some dacite blocks show prismatic jointing, suggesting an origin of hot emplacement and subsequent rapid cooling, possibly resulted from collapse of a steep lava front. Some samples have glassy groundmass and rhyolite-like flow texture, with presence of mafic inclusions and bread crust bomb texture. The surface of the O'Higgins Glacier is covered by lapilli-size pumice fallout deposit. There are many dirt cones covered by volcanic ash composed of pumice fragments, volcanic glass, quartz, plagioclase, biotite, hornblende, and orthopyroxene. The ash and pumice are similar in chemical composition, both indicating an adakitic signature. At least three layers of fallout deposits have been recognised in parts of the surface of the glacier, which may correspond to the latest known eruptions. Reconocimiento geológico del volcán Lautaro, Patagonia chilena. El volcán Lautaro es el más próximo alPunto Triple de la dorsal de Chile en la Zona Volcánica Austral de los Andes. El edificio volcánico de 3.607 m s.n.m. se destaca como el punto más alto en la parte noroeste del plateau del Campo de Hielo Patagónico Sur. El basamento del volcán está compuesto por metapelitas de bajo grado metamórfico que están atravesadas por cuerpos tabulares constituidos por granitos de hornblenda-biotita. El volcán está casi completamente cubierto por hielo y el estudio se

show abstract