干旱区生态环境知识资源中心

A palynological investigation of 164 samples from 18 water wells in northern Kordofan, Sudan, enabled the recognition of five informal zones based on pollen and spore assemblages ranging in age from Albian to Maastrichtian. The youngest (late Campanian- Maastrichtian) assemblages are restricted to the Bagbag Basin, whereas Albian - Cenomanian (to Turonian) sediments are widespread to the east and west of the Bagbag area. Impressions of Salvinia floating leaves from outcrops of the upper Hamrat el Wuz Formation, western part of the study area, are among the oldest occurrences of this water fern and indicate a Campanian - Maastrichtian age for these sediments.

The vertical distribution of hygrophilous (pteridophytic spores) versus xerophilous (ephedroids and possibly small, weakly sculptured tricolporates) elements in the palynofloras suggests widespread moist of even aquatic habitats in the Albian - Cenomanian and Campanian - Maastrichtian. A shift towards drier conditions occurred in the late Cenomanian - Turonian. Throughout the Cretaceous, however, there may have been extensive arid/semiarid areas of non-deposition and seasonally dry periods. Some characteristics of the local palynofloras are attributed to its inner continental position. Rare Albian - Cenomanian and Campanian - Maastrichtian dinoflagellates could be interpreted as lacustrine phytoplankton rather than as evidence for marine influence.