Integrated palynology and sedimentology of the Mississippian of the Tisdafine Basin (Eastern Anti-Atlas, Morocco)

Abstract The Mississippian (Tournaisian–Visean) of the Jbel Asdaf area in Tisdafine Basin (Eastern Anti-Atlas, Morocco) has been, for first time, subject a palynological study. This work aims to describe lithological and paleontological composition Aït Yalla Tinerhir Formations, then refine age, reconstruct paleoenvironment assess thermal maturity organic matter. studied section is subdivided, from oldest youngest, into three intervals, according their compositions. Lithologically, lower interval (lower part Formation) middle (upper Formation basal consist mostly clay shales green shales, respectively, both alternating with limestone or sandstone beds. upper dominated by sandstones, also pelitic-sandstone kerogen delivered analyzed samples continental origin, composed mainly opaque phytoclasts, while translucent phytoclasts miospores are less represented. Marine fraction, consisting granular amorphous matter some phytoplankton, rare. Biostratigraphically, late Visean Tripartites vetustus – Rotaspora fracta (VF) miospore Zone Western Europe biozonal scheme recognized regards Formation, based on occurrence cf. knoxi . Vallatisporites aff. ciliaris another biostratigraphic marker taxon assemblage, whose last marks end VF Biozone at top section. Qualitative quantitative parameters different palynofacies constituents (e.g., shape, size, % phytoclasts) show, base section, gradual transition distal marine environment generally towards an intermediate suggesting sea-level fall. Optical analyses performed color palynomorphs, spores, suggest maturity, ranging mature early post-mature stage most analysed samples, burial depth temperature least 3300 m 90 °C, respectively.