STRUCTURAL CONTROL OF VOLCANIC ACTIVITY IN THE NORTHEAST AREA OF THE NEVADO DEL RUIZ VOLCANO, COLOMBIA

The Nevado del Ruiz Volcano (NRV), located in the Colombian Central Cordillera, has a high geothermal potential with an important energetic interest. Interpretation of aerial photographs and satellite imagines in conjunction with analysis of morphological, tectonic features and field data (fractures, joints and fault striations) of the NVR allow to infer a structural model that explains the pattern of location of hot springs in the Eastern part of the NVR.

Orientation of structures and kinematic indicators in the region are closely related to the dominant tectonic features of the NVR, nominally a NE-SW system (Palestine fault and Romeral fault) and a NW-SE to E-W system (Villamaría-Thermal fault trend). The Palestine fault is a right-lateral regional fault with a predominant N10° - 30°E direction, this orientation coincides with the alignment of Ruiz, Santa Isabel and other volcanoes suggesting a relationship between regional structures and magma supply as suggested previously by other authors (e.g., Calvache & Monsalve, 1983). The Villamaría-Thermal fault is a normal fault with a left-lateral component, which shows morphotectonic signs of recent activity such as the presence of aligned volcanic domes and deflected channels. Other local faults such as Campoalegre, San Ramon and Rio Claro may also play a role in the distribution and spatial location of the hot springs southeast of the NVR.