Miocene andesitic lavas of Sierra de Angangueo: a petrological, geochemical, and geochronological approach to arc magmatism in Central Mexico

The Cuitzeo granitic xenolith: evidence of an Early Miocene magma plumbing system in central Mexico

“…Major elements, trace elements and Sr-Nd isotopes of the studied granitic xenolith of the Czi are consistent with other granitic and granulitic xenoliths reported in the TMVB (Figure 5, and Table 3) (McBirney et al, 1987;Martin del Pozzo, 1990;Aguirre-Díaz et al, 2002;Schaaf et al, 2005;Corona-Chávez et al, 2006;Meriggi et al, 2008;Ortega-Gutiérrez et al, 2014), as well as in the SMC-MALSA volcani<c sequences (Verma and Hasenaka, 2004;Gómez-Vasconcelos et al, 2015;Hernández-Bernal et al, 2016 (Middlemost, 1994) indicates a sub-alkaline trend, which is also similar to the granitic xenoliths reported for the TMVB and granulites of the Valle de Santiago volcanic field and Amealco Caldera (Figure< 1 and 5a). In addition, the sample falls into the granite field, similar to xenoliths found within products of the Paricutín Volcano, which is the youngest of the MGVF (Foshag and González, 1956), whereas other granitic xenoliths of the TMVB are gabbrodiorite-diorite in composition.…”

“…The first one is exposed at the ENE-WSW oriented Sierra de Mil Cumbres (SMC) highland, which is 20 km wide and 60 km long, exposed to the south of the city of Morelia (Pasquarè et al, 1991;Gómez-Vasconcelos et al, 2015). The second one is exposed at Sierra de Angangueo (MALSA), which is a NNW-SSE elongated and prominent, 35 km -long landform (Hernández-Bernal et al, 2016). The SMC-MALSA Miocene volcanic sequences contain exposures of chemically-bimodal volcanism in the form of andesitic-dacitic lava flows, ignimbrites and some basaltic cinder cones.…”

“…The SMC-MALSA Miocene volcanic sequences contain exposures of chemically-bimodal volcanism in the form of andesitic-dacitic lava flows, ignimbrites and some basaltic cinder cones. Their corresponding K-Ar and Ar-Ar ages range between 24 and 14 Ma (Pasquarè et al, 1991;Gómez-Vasconcelos et al, 2015;Hernández-Bernal et al, 2016). According to previous work, the known ages for the SMC-MALSA volcanic sequences between 24 and 18 Ma correspond to voluminous eroded early Miocene andesitic (±dacitic) stratovolcanoes, which are overlain by ignimbrites, debris flow deposits and debris avalanche deposits related to the evolution of scattered calderas and showing ages between 18 and 16 Ma.…”

Physical-mechanical behavior of fresh and completely altered rocks as an important factor of slope instability in the El Rosario Monarch Butterfly Sanctuary, Michoacán, Mexico

“…El Campanario hill, with an elevation 3640 m a.s.l., is the highest peak of the Sierra de Angangueo and is the main sanctuary of the Monarch Butterfly Biosphere Reserve (MBBR), located nearby the El Rosario locality (Figure 1c, 2). The hydrothermal alteration zone in El Campanario hill is associated with the mineral deposits of the Angangueo Mining District (Ostrooumov, 2014;Hernández-Bernal et al, 2016). This alteration process was correlated with the 2010 landslides that partly swept the town of Angangueo, Michoacán (López-García and Alcántara-Ayala, 2012).…”

“…The oldest exposed rocks in the area are of Lower Cretaceous age and correspond to a metamorphosed sequence of andesite and volcano-sedimentary sediments interstratified with metalimestone, metalutites and metasandstone (Campa et al, 1981;Campa and Coney, 1983). On top of these old lithological successions, the volcanic rocks of Sierra de Angangueo are exposed (Pasquaré et al, 1991;SGM, 2000;Ferrari et al, 2012;Hernández-Bernal, 2016). The Sierra de Angangueo is made of three volcanic successions emplaced during the early-middle Miocene.…”