干旱区生态环境知识资源中心

Previously reported fossil assemblages in the Quseir Formation do not contribute to definite age assessment. The formation was assigned a middle to late Campanian age according to its stratigraphic position below the well-dated (Campanian-Maastrichtian) Duwi (Phosphate) Formation No palynological work has previously been carried out on the Quseir Formation. Some arenaceous foraminifers (Campanian and Maastrichtian) were recorded from the Quseir Formation at Gebel Abu Had and Gebel Duwi (Eastern Desert). In the present study well-preserved palynomorphs have been recovered from shales equivalent to the Quseir Formation, in the Kharga subsurface section, Kharga Oasis. The presence of relatively large angiosperm pollen (e.g. Tricolpites spp., > 25 mu m) co-occurring with rare Dinogymnium dinocyst species indicate a Campanion age for the Quseir Formation. Moreover, pre-Turonian pollen (e.g. Classopollis and Eucommiidites) are lacking. The nature and frequency of the recovered palynomorphs imply shallow water deposition. This is essentially inferred from the high percentages of land-derived miospores associated with the dominance of palynofacies debris, accompanied by low percentages of marine dinoflagellate cysts. From the data, the deposition of the Quseir Formation began shallower tin the topmost parts of the formation) and were deepening upwards as documented in the overlying Duwi Formation.