The coastal formation of the edough: geological, sedimontological and géochimical approch, paleoenvironmental implication

Abstract

The study area, located along the Seraïdi Road in the northeastern part of Annaba within the Edough massif, represents a geologically diverse coastal zone. This research focuses on the calcarenite formations, aiming to define their sedimentological, mineralogical, and micropaleontological characteristics, while reconstructing the ancient depositional environment in which they formed.A multidisciplinary methodology was applied, including field observations and laboratory analyses such as quartz grain morphoscopy, calcimetry, X-ray diffraction (XRD), and micropaleontological examination of benthic foraminifera and ostracods. The results revealed a clear variation in sediment sources—some samples reflected a terrigenous siliciclastic influence, while upper samples pointed to a shallow marine carbonate-rich environment. Microscopic analyses identified benthic foraminifera such as Elphidium, Rosalina, and Quinqueloculina, as well as bryozoans and ostracods, indicating a stable, low-energy marine environment favorable to the preservation of microfossils. What distinguishes this thesis is its comparative perspective. Beyond the analysis of Seraïdi samples, it integrates findings from previous studies carried out in the Ain Bent Sultan and Cap de Garde areas. This synthesis, presented in a dedicated comparative section, provides a comprehensive geological interpretation of calcarenite facies variability across Annaba’s eastern coast, highlighting the interplay between marine and continental influences in dynamic sedimentary settings.