IGEBA   23946
INSTITUTO DE GEOCIENCIAS BASICAS, APLICADAS Y AMBIENTALES DE BUENOS AIRES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
RELEVAMIENTOS GEOFÍSICOS EN RÍO VALDÉZ, TIERRA DEL FUEGO: ESPESOR Y EXTENSIÓN AREAL DE DEPÓSITOS GLACI-LACUSTRES
Autor/es:
CORONATO, ANDREA; MARÍA JULIA ORGEIRA; QUIROGA, DIEGO; CLAUDIA PREZZI; PONCE, FEDERICO
Reunión:
Congreso; XX Congreso Geológico Argentino; 2017
Resumen:
In the Río Valdéz mouth, located in the southeasterrn coast of Lago Fagnano, an outcrop of lacustrine sediments with a thickness of ~7 m was identified. Taking into account geomorphological and sedimentological characteristics, such outcrop is interpreted as corresponding to a glaciolacustrine deposit with rhythmites, formed between the basal moraines of the Fagnano palaeoglacier, which occupied the Isla Grande de Tierra del Fuego center during the Late Pleistocene. Ground magnetic and resistivity surveys were carried out, trying to determine the thickness and areal extension of these lacustrine deposits. 1380 magnetic stations were measured with an approximate equidistance of 10 m. In the case of the geoelectric studies, five VESs (vertical electrical soundings) were performed. From the obtained results, a depth to the top of the lacustrine deposits of 4-5 m and minimum thickness of 11-12 m was inferred. Regarding their areal extension, the existence of three zones of maximum magnetic anomalies trending NNE-SSW, with a minimum longitude of 190 m and a maximum width of approximatelly 100 m was determined. To the north, the coalescence of these three elongated zones is observed, forming a unique positive magnetic anomaly. These new data complement sedimentological and paleomagnetic studies that are actually being carried out, contributing to the knowledge of the Upper Pleistocene glacial history of the centre of Tierra del Fuego.