Texturas superficiales en los granos de cuarzo de las arenas del Plioceno superior de la zona Jerez-Lebrija (SW de España)

Abstract

In the Jerez-Lebríja area (SW Spain) there are deppsits of Pliocene sands which are exploited in various quarries. The analysis of the surface features presented by the quartz grains from these sands refveals different stages in their evolution of the grains. The first of these stages is recorded in the form of conchoidal fractures and arcuate steps; the second is represented by an assemblage of features comprising isolated Vs, grooves and chattermark trails. In a posterior stage chemical features were developed in relation to tropic climatic Conditions