Coptocampylodon? rhaeticus n.sp., a New Problematic Microfossil (“incertae sedis”) from the Rhaetian Dachstein Limestone of the Northern Calcareous Alps (Germany, Austria)

A new problematic microfossil is described as Coptocampylodon? rhaeticus n.sp. from the Rhaetian Dachstein Limestone of the Northern Calcareous Alps. The new species is composed of a long cylindrical and an irregular rounded body, both showing narrow axial cavity. It is similar to Coptocampylodon? elliotti RADOICIC 1969 from the Cenomanian of Montenegro, but lacks the longitudinal grooves in the cylindrical part. In the Alpine Dachstein Limestone it has been detected at several localities where it occurs as an abundant constituent of biosparitic limestones along with the benthic foraminifera Triasina hantkeni MAJZON, Aulotortus sinuosus WEYNSCHENK, Duostominidae and dasycladales Griphoporella curvata (GÜMBEL) and Diplopora adnetensis FLÜGEL

Age, microfacies and depositional environment of the Middle to Late Paleocene shallow-marine carbonates in the Sirt Basin of Libya (Upper Sabil Formation) : "Are Intisar domal structures pinnacle reefs?"

In the central-eastern Sirt Basin, enigmatic Intisar domal structures host significant hydrocarbon accumulations. These structures have been commonly interpreted as pinnacle reefs/bioherms occurring in the open-marine basinal environment. Generally, pinnacle reefs/bioherms are mainly characterized by in situ carbonates. The current study challenges the Intisar pinnacle reef/bioherm model by examining one of the domal structures in terms of biostratigraphy, microfacies and depositional environment. These structures were dated using larger benthic foraminifera, which yielded a Middle to Late Paleocene age (Selandian–Early Thanetian). Thirteen microfacies types representing different carbonate ramp environments ranging from outer ramp to inner ramp, were defined. Outer ramp deposits have been observed adjacent to the domal structure, represented mainly by wackestone with small benthic and planktonic foraminifera. The outer ramp deposits are most likely isochronous to the domal structures. The lower part of the domal structures is composed mainly of foraminiferal–algal–echinodermal packstones. The upper part is characterized by foraminiferal–algal–echinodermal packstones with intercalated microbialite–coral boundstones. The euphotic inner ramp deposits are preserved on the crest of the domal structure, consisting of grainstone and packstone rich in Glomalveolina. As a result of this study, the Intisar domal structures are seen as erosional relics of a carbonate ramp and no evidence for pinnacle reef/bioherm model was found