Geology and stratigraphy of the Mexico Basin (Mexico City), central Trans-Mexican Volcanic Belt

Abstract

We present a new geological map of the Mexico Basin (Mexico City) based on field descriptions, a compilation of data from previous publications, and new 40Ar/39Ar geochronology data. The oldest rocks described in the Mexico Basin are Cretaceous limestones, overlaid by Oligocene (26.0 Ma) and Miocene (22.8–5.0 Ma) volcanic successions, followed by Pliocene-Pleistocene (3.7–1.2 Ma) to Recent volcanic rocks around the basin. The Mexico basin is surrounded by volcanic ranges mainly andesitic and dacitic in composition: Sierra de Guadalupe (∼20 to ∼13 Ma), Sierra de las Cruces (3.7–0.03 Ma), Sierra Nevada (1.4 Ma to Recent), and Sierra de Chichinautzin (1.2 Ma to Recent). The basin has formed and evolved through complex tectonic and volcanic events: A NNW and NNE-Cañón de Lobos trending reverse fault affected the Cretaceous basement, the NW-SE Mixhuca normal fault displaced Oligocene-Miocene volcanics, the NE-SW Tenochtitlan fault system displaced Plio-Pleistocene rocks, and finally E-W normal faults affected the most recent volcanic rocks, paleosols, and lacustrine sediments.