Repositorio Digital Sernageomin
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Review of bomb and ash flows : Genesis and case studies of a subset of block and ash flow deposits
Get PDFPyroclastic density currents with an abundance of cauliflower-shaped bombs are an uncommon type of deposit, called bomb and ash flow (BoAF) deposits in several papers. Although they are similar to block and ash flow (BAF) deposits (e.g., rich in juvenile blocks and breadcrusted bombs), they are often related to eruptions of mafic to intermediate magmas. In the current study, we analyze and compare historical and prehistorical BoAF-generating eruptions at Asama and Aso (Japan), Mayon (Philippines), Mt. Spurr (United States), Fuego (Guatemala), Arenal (Costa Rica), Cotopaxi and Tungurahua (Ecuador), and Láscar and Tilocálar volcanoes (Chile). Our review indicates that BoAFs show a substantial contribution of juvenile rounded material but with different rheologies and fragmentation mechanisms. This juvenile material is typically basaltic or andesitic, as it is more susceptible to form volcanic bombs with scoriaceous cauliflower textures. Thus, BoAFs could be a subset of the BAF deposits. The study and recognition of this type of deposit in volcanic sequences could be misinterpreted as a ballistic bomb deposit or even a hot bomb-rich lahar deposit, therefore, its appropriate interpretation is fundamental for volcanic hazard assessment.pp.346-37
Evaluación de remoción en masa en Estero Sin Nombre, sector caleta Rollizo, Ralún, región de Los Lagos
No full textInforme Técnico -- Unidad Ejecutora: Oficina Técnica Puerto Varas13 p
Geología de las áreas Cupo-Toconce y Cerros de Tocorpuri, región de Antofagasta
No full textContiene Anexos: Anexo I.Dataciones Radiométricas ; Anexo II.Fósiles ; Anexo III.Análisis Químicos ; Anexo IV.Difractometría de Rayos X ; Anexo V.Microscopía Electrónica de Barrido ; Anexo VI.Depósitos Minerales ; Escala: 1:100.000 ; Coordenadas: 22°00´ y 22°30´ S / 68°30’ y 68°00’ E223 p
Caracterización hidrogeológica del área afectada por la subsidencia del 30 de julio de 2022 en la mina Alcaparrosa, Tierra Amarilla, región de Atacama, Chile
No full textInforme Registrado IR-23-104142 p
Gravimetría del área La Unión-Hueicolla, regiones de Los Ríos y Los Lagos, Chile
Get PDFInforme Registrado IR-23-10751 p
Evaluación de remoción en masa en la ruta X-91, comuna de O’Higgins, región de Aysén del General Carlos Ibáñez del Campo
Get PDFInforme Técnico -- Unidad Ejecutora: Oficina Técnica de Coyhaique, Unidad de Asistencias Técnicas y Emergencias Geológicas11 p
Chronology of the Bayo River valley deglaciation and implications for the Late Pleistocene Atlantic-to-Pacific drainage reversal of the General Carrera-Buenos Aires palaeolake, Patagonia-Chile
No full textWe present a study on the glacial and paraglacial geomorphology of a Patagonian Cordillera Valley that is key to understanding evolution of the great lakes of Patagonia. 10Be cosmogenic nuclide exposure ages of ice-moulded surfaces from the Bayo River Valley confirm that the valley became ice-free before 13.4-14.2 ka. This valley constituted the first outlet of the Chelenko Lake, precursor of the General Carrera-Buenos Aires Lake (GCBAL), toward the Pacific Ocean. This age constrains the timing of the lake drainage reversal from the Atlantic Ocean to the Pacific Ocean. Alluvial fans and terrace levels recognized in the eastern segment of the valley at the same altitude as terrace levels observed in the GCBAL basin confirm that the Bayo Pass controlled the elevation of the lake once the drainage reversed to Pacific Ocean. 10Be cosmogenic nuclide exposure ages also confirm that the maximum advance of the Exploradores Glacier since its major retreat >13.4-14.2 ka ago occurred during the Little Ice Age, the last remnant of glacial drift in these valleys.pp.1-2
Visita Técnica por Remociones en Masa en Ruta N-55, Sector Las Trancas, Comuna de Pinto, Región del Ñuble
No full textRevisor: Alejandro Alfaro -- Informe Técnico -- Unidad Ejecutora: Unidad de Asistencias Técnicas y Emergencias Geológicas. Santiago15 p
Visita técnica por remoción en masa en la ruta X-550, comuna de Aysén, región de Aysén del General Carlos Ibáñez del Campo
No full textInforme Técnico -- Unidad Ejecutora: Oficina Técnica de Coyhaique, Unidad de Asistencias Técnicas y Emergencias Geológicas16 p
