The structural architecture of the Los Humeros volcanic complex and geothermal field

The Los Humeros Volcanic Complex (LHVC) is a large silicic caldera complex in the Trans-Mexican Volcanic Belt (TMVB), hosting a geothermal field currently in exploitation by the Comisión Federal de Electricidad (CFE) of
Mexico, with an installed capacity of ca. 95 MWof electric power. Understanding the structural architecture of
LHVC is important to get insights into the interplay between the volcano-tectonic setting and the characteristics
of the geothermal resources in the area. The analysis of volcanotectonic interplay in LHVC benefits fromthe availability
of subsurface data obtained during the exploration of the geothermal reservoir that allows the achievement
of a 3D structural view of the volcano system. The LHVC thus represents an important natural laboratory
for the development of general models of volcano-tectonic interaction in calderas. In this study, we discuss a
structural model of LHVC based on morphostructural and field analysis, integrated with well logs, focal mechanism
solutions and magnetotelluric imaging. The structural analysis suggests that inherited regional tectonic
structures recognized in the basement played an important role in the evolution of the magma feeding system,
caldera collapses and post-caldera deformations. These inherited weak planes have been reactivated by resurgence
faults and post-caldera magma-driven hydrofractures under a local radial stress field generated by the
shallow LHVC magmatic/hydrothermal system. The local stress field induced caldera resurgence and
volcanotectonic faulting. The results of this study are important to better constrain the structural architecture
of large caldera complexes. Also, our study is useful to understand the structure of the Los Humeros geothermal
field and support the exploration of deeper Super-Hot Geothermal Systems (SHGSs) and engineering of Enhanced
Geothermal Systems (EGSs) for electric power production in the LHVC and other active resurgent
calderas.