Geomorphic assessment of active tectonics in the Acambay graben, Mexican Volcanic Belt

Abstract

Spatial variations of Quaternary deformation and tectonic activity of faults along the Acambay graben are assessed using geomorphic and morphometric approaches. The Acambay graben is an east-west trending structure of apparent Quaternary age, located in the central part of the Mexican Volcanic Belt, which gives rise to pronounced scarps over a distance of about 80 km. Continuing tectonic activity in the Acambay graben is confirmed by recent well documented seismic episodes.The intensity of active tectonics has been interpreted through a detailed geomorphic study of the fault-generated mountain fronts and fluvial systems. The combined geomorphic and morphometric data provide evidence for relative variations in tectonic activity among the Acambay graben faults. Geomorphic indices suggest a relatively high degree of tectonic activity along the Venta de Bravo and the Acambay-Tixmadeje faults, followed, in order of decreasing activity, by the Pastores, Temascalcingo and Tepuxtepec faults. Spatial variations within faults have also been identified, suggesting a higher level of tectonic activity at the tips of the faults. This pattern of variation in the relative degree of tectonic activity is consistent with field evidence and seismic data for the Acambay graben. Geomorphic evaluation of the Acambay graben faults suggests that the Acambay-Tixmadeje and Venta de Bravo faults, and specifically the tips of these faults and a central segment near the town of Venta de Bravo, should be considered as areas of potentially high earthquake risk.

Tectonic analysis of the Honaz Fault (western Anatolia) using geomorphic indices and the regional implications

“…The uplifted and subsided blocks produced by normal faults in rift valleys exhibit remarkable geomorphic markers, and the use of quantitative measurements of features such as drainage systems, axial rivers, triangular facets and mountain front sinuosities play a prominent role in revealing tectonic activity in continental extensional provinces (Bull, 1977;Bull & McFadden, 1977;Gürbüz & Gürer, 2008;Keller, 1986;Keller & Pinter, 2002;Özkaymak & Sözbilir, 2012;Pérez-Peña, Azor, Azañón, & Keller, 2010;Ramirez-Herrera, 1998;Silva, Goy, Zazo, & Bardají, 2003;Viveen et al, 2012;Wells et al, 1988). Western Anatolia provides a natural laboratory for graben and horst morphology that has evolved since the early Quaternary (Bozkurt, 2001;Bozkurt & Sözbilir, 2004, 2006Koçyiğit, 2005;Koçyiğit, Yusufoğlu, & Bozkurt, 1999;Paton, 1992;Seyitoğlu, Tekeli, Çemen, Şen, & Işık, 2002;Sözbilir, 2001Sözbilir, , 2002Sözbilir, , 2005.…”

Geomorphic Analysis in Determining Tectonic Activity Affected by Sumatra Fault in Liwa Region and Its Surrounding Area, Lampung, Indonesia

“…• Lf is the cumulative length of the triangular facets on a mountain face; • Ls is the overall length of the face of the mountains pulled straight (Wells et al, 1988;Ramirez-Herrera, 1998). …”

“…The morphology of small to medium sized channels and valleys that cross mountain fronts may reflect the impact of local base-level changes due to relative uplift along active structures associated with frontal escarpments (Wells et al, 1988;Ramirez-Herrera, 1998). This study uses a ratio analysis of the base width and height of Reflect a balance between the tendency of stream and slope processes to produce irregular (sinuous) mountain front and vertical active tectonics that tend to produce a prominent straight front (Keller, 1986 Bifurcation ratio is a ratio between a number of total segments in an order with the higher order.…”

Relative tectonics and debris flow hazards in the Beijing mountain area from DEM-derived geomorphic indices and drainage analysis

“…A low value reflects a nearly round basin and tectonic activity is weak (El Hamdouni et al, 2008). The values of the B s index are divided into five categories according to Ramirez-Herrera (1998) …”