Relevamientos geofísicos en estructuras circulares en Telsen (Chubut): implicancias genéticas.

PREZZI, CLAUDIA BEATRIZ; NAVARRO, EDGARDO; MARÍA JULIA ORGEIRA; ASTINI, R.

Congreso; XX Congreso Geológico Argentino; 2017

Geophysical surveys in circular structures in Telsen (Chubut): genetic implications. Two sub-circular structures with diameters of approximately 2 km, developed in volcano-sedimentary deposits, were recognized near Telsen, to the northeast of Chubut province. Different hypotheses have been proposed about the genesis of these structures including magmatism, freatomagmatism and impact events. Trying to determine the mechanism responsible for the formation of these structures, magnetic and electromagnetic ground surveys were carried out. 2643 magnetic stations with an equidistance of approximately 15-20 m were measured. Electromagnetic profiles were surveyed using five different frequencies. Large amplitude and short wave length magnetic anomalies in the center of both structures were detected. Moreover, higher apparent electrical conductivities were registered in coincidence with the magnetic anomalies. The obtained results would indicate the existence of not-outcropping rocks with high magnetic susceptibility and high electrical conductivity in the centre of the studied structures. This last fact suggests that the genesis of these circular structures would be related to magmatic or phreatomagmatic processes.