Geology of the Sierra de Santa Rita, Zacatecas, Mexico

Information concerning the southern extent of the Mexican geosyncline was desired with the mapping of Sierra de Santa Rita, near Concepción del Oro, Zacatecas, in northern Mexico. Three Upper Jurassic and six Cretaceous formations were mapped, within which lithology and changes in thickness do not reflect proximity of this area to ancient shore lines. The first description of the Huizachal formation in northern Zacatecas is given