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…

This paper summarizes mineralogical results from temperate, subtropical and tropical soil chrono- and climosequences and aims to understand the role of the factor time for the formation of kaolinites. A mid-Pleistocene welded F6-paleosol at Stari Slankamen, Serbia, developed discontinuously in…

In two earlier papers (Verma and Quiroz-Ruiz, 2006, Rev. Mex. dene. Geol, 23,133-161, 302-319) precise critical values for normal univariate samples of sizes n up to 100 have been reported. However, for greater n, critical values are available only for…

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…

Detrital zircon U-Pb geochronology from each of the formations of the Triassic-Lower Jurassic Barranca and El Antimonio groups of central and northwestern Sonora and from the Lower Jurassic Basomari and Middle Jurassic Lily formations of northern Sonora indicate they contain…

Major, trace and rare earth elements (REE) study was carried out on the Lower Cretaceous Dalmiapuram Formation in southeastern India in order to understand the geochemical variations among various litho-units. Coral algal limestone (CAL) shows high content of CaO (53…

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…

The statistically correct handling of compositional data requires log-ratio transformation whereas the multivariate technique of linear discriminant analysis (LDA) assumes a normal distribution of the transformed variables. In addition to other requirements, both these aspects were considered for proposing five…