Geophysical evidence of first stages of inflation in Domuyo volcanic center in northwestern Neuquén province, Argentina

GODOY, LAURA B.; NACIF, SILVINA; LUPARI, MARIANELA; GARCÍA, HÉCTOR P.A.; CORREA-OTTO, SEBASTIÁN; MELCHOR, IVÁN; PECHUAN, STEFANIE N.; ARIZA, JUAN P.; GIMENEZ, MARIO; CASELLI, ALBERTO

JOURNAL OF SOUTH AMERICAN EARTH SCIENCES

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2020

0895-9811

Cerro Domuyo, in northwestern Neuqu� en province of Argentina, shows notable geothermal activity, although itis located at a considerable distance from the actual volcanic arc. Many studies have been developed in this areawith the aim of investigating its geothermal field. Despite these efforts, the characterization of the dynamicactivity in the area is still poorly known. This work shows the results of a network of seismological stations,which registered volcano-tectonic, long-period and hybrid events. A large number of volcano-tectonic eventsconcentrated mostly in the Cerro Domuyo geothermal area were detected. These events can be divided into twogroups, thosethat occurred at shallow depths below the geothermal area and those at greater depths below thehigh region of Cerro Domuyo. Shallow events were located around the Manchana Covunco fault and many ofthem were particularly clustered at its intersection with the Humazo fault. Seismicity in the area shows that thesefaults are continually active due to fluid movement, as was evidenced by the hydrothermal manifestation of theHumazo in 2003. Moreover, new studies provide evidence that the Cerro Domuyo is experiencing an importantinflation caused by a magmatic body. Deep volcano-tectonic events are evidencing this activity. Considering thelarge distance between the actual volcanic arc and the study region, and the high density of shallow volcanotectonic events, it is highly likely that this magmatic body is increasing the geothermal activity. Additionally,the aeromagnetic anomaly over Cerro Domuyo is showing a thin magnetic crust of less than 6 km, suggesting aclear link between the geophysical results and the inflation in Cerro Domuyo.