Datos paleontológicos y tafonómicos de la formación Turre en Cortijada de Arejos (Almería)

Abstract

The Turre Formation consists of two Members: the Lower or Azagador, wich lies unconformable on the metemorphic basement, and the upper or Abad. In the Cortijada de Arejos section, in the Almería province, the Azagador Member is 19 m. thick, and consists of arenites and conglomerates build up of fragments of Paleozoic rocks in a calcareous cement. The Abad Member, represented only by the lowest part, is unconformably overlain by the Pleistocene and consists of sandstones, claystones and marls. The macrofauna is only abundant in the Azagador Member. It consists of Bryozoa, with the vinculariform, celleporiform and membraniporiform types the most important; Brachiopoda (Terebratula sinuosa and Hemithiris); Mollusca (Chlamys scabrella, Ostrea, Spondylus crassicosta and Cirsotrema lamellosum) as well as some rhodolites. The taphonomic features and the growing forms of the Bryozoa show that the Azagador Member was formed in a quiet environment, with periods characterized by low rate of sedimentation and weak currents. The activity of the boring organism such as Cliona, Spathipora, and Polydora on Bivalvia and Brachiopoda, as well as the predominance of the epifaunal components and the lack of deposit feeders, is to be emphasized. The presence of Globorotalia mediterránea in the Abad Member indicates a Messinian age for the Turre Formation. The absence of this fossil in the Azagador Member is explained by the different environmental conditions. Therefore, taking into account the unconformity of the Azagador Members on the basement, is also included in the Messinian.