Carta geomorfológica de la sección central y occidental de la Región Metropolitana de Santiago

Abstract

RESUMENSe presenta la carta geomorfologica de la mitad occidental de la Region Metropolitana de Santiago. En ella se definen unidades lito-morfologicas que facilitan el analisis de los sistemas de laderas, con el objeto de generar unidades o sistemas homogeneos de vertientes, en que la base de la interpretacion morfodinamica se sustenta en la naturaleza litologica de los materiales. Estructuralmente, se destacan los relieves en estructuras monoclinales, resaltando la geologia de los estratos y no la posicion en el monoclinal, pues dado el ambiente de media y baja montana, geodinamicamente, operarian de manera similar. En los relieves graniticos se distingue la presencia de superficies de erosion residual. Se incorpora tambien en las formas aluviales, la nocion de terrazas segun edad, distinguiendo entre pleistocenicas, holocenicas, e indeterminadas. Finalmente, como resultado se generan poligonos de unidades de similar morfogenesis, litologia y geodinamica actual.Palabras claves: Mapa geomorfologico sistemas de vertientes, sistemas depositacionales, estructura. ABSTRACTThe geomorphologic chart of the western part of the Santiago Metropolitan Region was made considering a lito-morphologic unit's definition purpose, especially for the interpretation and classification of homogenous slope systems. The chart goal was the identification of homogenous slopes systems, in which the base of the morpho dynamic interpretation is sustained in the geologic nature of the materials. Structurally, the monoclinals reliefs are emphasized. Also, the lithological nature of the layers and not it position in the monoclinal is considered into the analysis of the medium and low mountain environment because, from a geodynamic point of view, they generally operate in a similar way. In the intrusive relief's, remnants of erosional surfaces are distinguished. The notion of tenaces is also considered in the alluvial forms according to age, distinguishing between pleistocenic, holocenic, and indeterminated tenaces. As results, polygons of units of equal morphogenesis, lithologic and present geodynamics are generated.

Geohazards in the Fjords of Northern Patagonia, Chile

“…The fieldwork was done in January and May 2016 and February 2017. A geomorphological classification for Andean cordillera environments was used [39], combined with lithology and morpho-structure [40]. Furthermore, an inventory of the fjord's hanging lakes and glaciers was completed.…”

“…Landslide inventory: A photointerpretation of aerial photographs (1982, 1997, 1:20,000 and 1:70,000) and Google Earth was completed and validated by fieldwork. Landslides were identified by morphological evidence, according to the criteria of Náquira [45], Sepúlveda and Serey [30] and Sepúlveda et al [32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47] for fjord environments. Vegetated landslides were also identified that occurred in the past but at unknown dates.…”