In many states of central Mexico, hardened volcanic materials called tepetate (hardened layers from tuff) cover large proportions of the land surface, and are therefore of economic and social importance. Under natural conditions, tepetates are unproductive due to their hardness…

The Quaternary Sierra Chichinautzin volcanic field (SCVF) is located at the volcanic front of the Trans-Mexican Volcanic Belt (TMVB), 350 km from the Middle American trench where the Cocos plate subducts beneath the North American plate. The SCVF…

The Mesozoic succession of the Sierra de Zacatecas (SZ) was originally described in two sequences. The older is the La Pimienta Phyllite or sometimes termed Zacatecas Formation (ZF) of presumably Late Triassic age based on paleontological constraints obtained at the…

We examined an east-west transect from the Gulf of California to the volcanic province of the Sierra Madre Occidental (28°30'N). The transect is divided into three geologic regions: 1) The coastal region (COR) is characterized by scattered exposures of Laramide…

The Arizpe sub-basin located in the northern part of the Río Sonora basin is a Basin and Range half-graben that initiated during Late Oligocene time in north-central Sonora. Its ~2.1 km-thick, east-dipping volcanic and sedimentary fill assigned to the Báucarit…

Islas Marías archipelago is located 110 km NW of San Blas, Nayarit in the mouth of the Gulf of California. The archipelago is formed by San Juanito, María Madre, María Magdalena, and María Cleofas islands. The position of these islands…

El acuífero del Valle de Toluca, localizado en el Altiplano Mexicano, se encuentra sometido a una intensa explotación para cubrir las necesidades de agua en el propio valle, así como parte de las de Ciudad de México. Los altos niveles…

Aim The purpose of this study was to examine the biogeographical relationships of the tree flora of the Yucatan Peninsula (YP2). To this aim we: (1) evaluated the affinities of political entities of tropical America with the Yucatan Peninsula, considering…

Knowledge of the population dynamics of tropical trees has expanded considerably in the past 20 years. An important observation deriving from these investigations is the confirmation that population behaviour varies both in time and space. A tool recently developed to…

Background The current lifetime prevalence of depression among females in Mexico is 9.1% and 2.9% among males. The overall lifetime prevalence of depression is 6.2% among the general population of Mexico. Individuals that experience depressive symptomology at a young age…