First calcareous nannofossil record from the Jurassic strata exposed in the Blue Nile Basin (Ethiopia)

摘要

Based on the first ever nannofossil record from the Blue Nile Basin (Ethiopia), new ages spanning Early Callovian to Late Tithonian are proposed for the Antalo Limestone. This contribution also documents the first detailed stratigraphy of the Mugher area (Blue Nile Basin) along with its characteristic bioelements and the occurrence of trace fossils. Based on field observations, sedimentological and faunal content, a paleoenvironmental model is also proposed along with an inferred relative sea level curve. The depositional environment ranges from supratidal to middle neritic (middle ramp) settings with paleodepth not exceeding 50 m.