Resumen de Los depósitos caoliníticos del Albiense en el sector de Estercuel -Gargallo (Cubeta de Oliete, Teurel): análisis mineralógico y textural
María José Mayayo Burillo, Alfonso Yuste Oliete, Blanca Bauluz Lázaro, Constanza Fernández-Nieto Fernández, J. M. González López
The kaolinite-rich detrital deposits from Estercuel-Gargallo sector (province of Teruel, Spain) correspond to clay-sand series from the Escucha and Utrillas Formations (Lower Cretaceous). The present study is focused on the mineralógica!, textural and morphological features of the kaolinite that is the main clay mineral in these series. We have characterized by X-ray diffraction (XRD), optical and scanning electron microscopy (SEM) the mineralogy of 29 samples, and specially the kaolinite texture and morphology. The studied samples are carbonate free, organic mater-rich and mainly composed of quartz, kaolinite and micaceous phases. These clay minerals are present in silt and clay fractions although kaolinite is mainly concentrated in the clay fraction. SEM observations show that kaolinite occurs in several different modes, indicating both detrital and diagenetic origin. Detrital kaolinite appears as alotriomorphous crystals filling pores between clastic grains, or constituting the planar fabric in finer lithologies. Diagenetic kaolinite consists of single hexagonal plates and stacks of hexagonal crystals (blocky and vermiform kaolinite). Furthermore mica-kaolinite intergrowths have been also identified, in which kaolinite can be both detrital and diagenetic.
