Repositorio Digital Sernageomin
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Remociones en masa asociadas al sistema frontal del 29 al 31 de Enero de 2021, quebrada de Macul, comuna de Peñalolén, región Metropolitana
No full textRevisor: Alejandro Alfaro S.29 p
Magnetic fabric of the Parashi stock and related dyke swarm, Alta Guajira (Colombia): The Caribbean-South American plates oblique convergence
Get PDFAnisotropy of magnetic susceptibility (AMS) and anhysteretic remanence (AAR) were used to evaluate the emplacement history of the Parashi stock and related dyke swarm situated in NW Colombia. The average magnetic susceptibility of 4.5×10-2 SI, in conjunction with low-coercivity components provided by the isothermal remanence and thermomagnetic curves with net Verwey and Curie transitions, indicates that multidomain magnetite records the anisotropy directions. The similar orientation and shape of the AMS and AAR ellipsoids indicate the absence of very fine magnetite with an inverse fabric. The magnetic foliation is the best-defined fabric element in these rocks and outlines a concentric structure, elongated parallel to the NE-SW direction of the pluton. Crystallisation age of the stock and dykes (51-47 Ma), along with pressure of emplacement determination indicate that the stock and the dyke swarm probably formed simultaneously, and they were emplaced in the shallow crust (<10 km). The magnetic fabric agrees with emplacement in a transtensional setting, with the dyke swarm infilling tensional cracks formed during the final stages of pluton crystallisation. This tectonic setting likely records the difficulty of the thick oceanic crust subducting, which would result in general transtension in the overriding continental plate and cessation of arc magmatism in the Eocene.pp.219-23
Reporte de asistencia técnica: sector villa Concepción, comuna de Laja, región del Biobío.
No full textRevisor: Alejandro Alfaro5 p
Diffuse gases in soil of Araró-Simirao geothermal system, Michoacán, Mexico
No full textThe Araró-Simirao geothermal system is located in the southeastern part of the Cuitzeo Lake depression, in the central part of the TransMexican Volcanic Belt (TMVB) province. It is a convective hydrothermal system dominated by sodium chloride water and high boron content. The thermal springs mainly release CO2 and lower concentrations of H2S, H2, and noble gases (He, Ne, and Ar). The aim of this study was to delimit the upflow areas in this geothermal system by determining the relationships between diffuse gas emission concentrations in soils and the zones of the greatest plausible permeability. Three sampling campaigns were carried out in 2018 (August and November) and 2019 (May). In these campaigns, diffuse gas emission in soils (CO2, Rn, and Hg vapors) and soil temperature were measured. The diffuse gas emission measurements ranged from 0.8 to 1,421 g m-2d-1 for CO2 flux, from 0.49 to 2,914 ng/m3 for gaseous elemental mercury (GEM), from 1,060 to 124,100 Bq/m3 for 222Rn, and from 0 to 7,511 Bq/m3 for 220Rn. The highest values were obtained in the dry season (May). Several anomalous zones of CO2 fluxes, GEM, and 222Rn were found to match faults and lineaments, interpreted as the greatest permeability zones. The zone with the highest values of these three parameters was located in the so-called mud pool at the crossing of the Araró-Simirao fault with a NW-SE (south zone) lineament, which is associated with the upflow zone of the system. Other anomalous zones were located in fracture and/or lineament zones in the central and northern parts of the system, which are associated with the outflow zone. According to the data obtained herein, CO2 could work as a carrier of Hg and 222Rn in the upflow zone; and this gas may be dissolved in the groundwater in the outflow zone.pp.496-51
Reporte de visita técnica : Posta de salud rural sector El Poncho, comuna de Puerto Octay, región de Los Lagos
No full textInforme Técnico -- Unidad Ejecutora: Oficina Técnica Puerto Varas6 p
Peligros del volcán Hornopirén, región de Los Lagos
No full textContiene Anexos: Anexo I.Catastro de Erupciones ; Anexo ; II.Edades Radiométricas ; Anexo III.Glosario ; Escala: 1:50.000 ; Coordenadas: 41°52'S / 72°26'O51 p
Análisis geológico del sobrevuelo del 5 de junio de 2020 en la cuenca del río Las Minas, comuna de Punta Arenas, región de Magallanes y la Antártica Chilena
No full textRevisor: Carolina Jara I. y Alejandro Alfaro S.25 p
Zonificación de susceptibilidad de remociones en masa en la ruta G-455, comuna de San José de Maipo, región Metropolitana
No full textRevisor: Alejandro Alfaro ; Contiene Anexos: Anexo I.Datos de Estaciones Hidrometeorológicas; Anexo II.Catastro o Mapa Inventario de Remociones en masa ; Anexo III.Mapas de Susceptibilidad a remociones en masa representados a escala 1:10.00059 p. + anexo
Evaluación de impacto en acuíferos y peligro de remoción en masa en laderas intervenidas en los loteos “Piedra Hueca-Pilolcura, El Canelal, Cutipay Alto y Cutipay 2”, comuna de Valdivia, región de Los Ríos
No full textRevisor: Carlos Johnson N. ; Código de identificación interno: INF-LOS RÍOS-10.202133 p
Gravimetría de la Hoja Constitución, región del Maule
No full textContiene Anexos: Anexo I.Tabla 1.Estaciones bases de gravedad ; Anexo II.Tabla 2.Densidad de muestras de rocas ; Escala: 1:250.000 ; Coordenadas: 35°00' - 36°00'S / 71°45' - 73°15'O44 p