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The Nevado de Toluca is an andesitic to dacitic stratovolcano of Late Pliocene–Holocene age located within the central and eastern sectors of the Trans Mexican Volcanic Belt. Morphostructural analysis, aerial photograph and satellite image interpretation, structural analysis and geological fieldwork were methods used to investigate the relationship between the evolution of the volcano and the tectonic framework of its basement. The study revealed that the area of Nevado de Toluca is affected by three main fault systems that intersect close to the volcanic edifice. These are from oldest to youngest, the Taxco–Querétaro, San Antonio and Tenango fault systems. The NNW–SSE Taxco–Querétaro fault system was active in the area since EarlyMiocene, and is characterized by right-lateral transtensive movement. Its reactivation during Early toMiddle Pleistocene was responsible for the emplacement of andesitic to dacitic lava flows and domes of La Cieneguilla Supersynthem. The NE–SW San Antonio fault systemwas active during Late Pliocene, before the reactivation of the Taxco–Querétaro fault system, and is characterized by extensional left-lateral oblique-slip kinematics. The youngest is the E–W Tenango fault system that has been active since Late Pleistocene. This fault systemis characterized by transtensive left-lateral strike-slip movement, and partly coeval with the youngest eruptive phase, the Nevado Supersynthem, which formed the present summit cone of the Nevado de Toluca volcano. The stress re-orientation from the Taxco–Querétaro to the Tenango fault system during Late Pleistocene is responsible for the < 1 Ma hiatus in the magmatic activity between 1.15 Ma and 42 ka. After this period of repose, the eruptive style drastically changed from effusive to explosive with the emission of dacitic products. The methodology presented here furnish new data that can be used to better assess the complex structural evolution of this sector of the Trans Mexican Volcanic Belt and to understand the influence of changes in the tectonic setting on the growth of volcanic edifices.

Detailed structural analysis was conducted on the E-W trending Tenango Fault System (TFS) at the western end of the La Pera Fault System, a major structure within the Trans-Mexican Volcanic Belt (TMVB). Field mapping, which included trenching the fault trace, revealed the displacement of recent volcanic deposits. The study indicates that the TFS is an active subvertical fault with transtensive left-lateral movement consistent with the contemporary stress regime in the region. The estimated Holocene slip rate is 0.3–0.5 mm/yr. The TFS activity constitutes an important seismic hazard in the intra-arc Lerma basin. Several towns are located within this basin and are particularly vulnerable to seismic risk because of its underlying strata consisting of lacustrine and volcaniclastic deposits (estimated maximum Mw 6.8–7). The TFS is an important structural element in the complex tectonic deformation history of central eastern TMVB and influenced the behavior of recent volcanism within the Lerma basin.

Volcanic hazard assessment is of paramount importance for the safeguard of the resources exposed to volcanic hazards. In the paper we present ELFM, a lava flow simulation model for the evaluation of the lava flow hazard on Mount Etna (Sicily, Italy), the most important active volcano in Europe. The major contributions of the paper are: (a) a detailed specification of the lava flow simulation model and the specification of an algorithm implementing it; (b) the definition of a methodological framework for applying the model to the specific volcano. For what concerns the former issue, we propose an extended version of an existing stochastic model that has been applied so far only to the assessment of the volcanic hazard on Lanzarote and Tenerife (Canary Islands). Concerning the methodological framework, we claim model validation is definitely needed for assessing the effectiveness of the lava flow simulation model. To that extent a strategy has been devised for the generation of simulation experiments and evaluation of their outcomes.

"Crustal stretching affecting western Mexico during the Neogene, and its relationship with the opening of the Gulf of California, has been widely studied and discussed for several decades. Nevertheless, the timing and kinematics of the opening is a matter of debate. Most authors essentially agree in considering the rupture of the lithosphere around the Gulf of California, as a fast process that began at ~12.5 Ma and became successful in the early Pliocene, when new oceanic crust began to form in the southern Gulf of California. However, recent studies demonstrated that the crustal stretching processes leading to the Gulf opening began in Late Oligocene as a wide rift, which subsequently focused into the present Gulf area in the early Miocene, accompanied by a slight change in the direction of extension. Eventually, after subduction ceased, highly oblique transtensional deformation broke the previously extended lithosphere. In this work we present a structural study of the kinematics and time of faulting, and of mafic dikes along three transects in the southern Sierra Madre Occidental, along the southeastern margin of the Gulf. We found that the deformation associated with the beginning of the Gulf of California rifting can be grouped in three sets: 1) normal faults formed during a first phase of deformation, beginning at ~24 Ma, characterized by E-W extension; 2) normal faults and dikes formed between ~20 and 11 Ma, associated with a second deformation phase, with ENE-WSW extension; 3) E-W to NE-SW oblique slip and strike-slip faults and dikes, associated with rift accommodation zones that segment the Gulf of California rift. No significant deformation occurred in the study area after 11 Ma, time at which the extension focused in the present Gulf region. The kinematics of faulting in the study area excludes that significant oblique or lateral deformation might have occurred during the initial phase of rifting in the southern Gulf of California, coincident with the last phase of subduction."