Problems of correlation in the Nubian sandstone facies

The “Nubian Sandstone Facies” is an epicratonic phenomenon, in which correlation is hampered by lithologic monotony, stratigraphic patchiness and the scarcity of index body fossils. In their place, trace fossils may substitute as environmental. paleogeographic and geochronologic guides, with trilobite burrows (Cruziana) providing a particularly high resolution. The established Cruziana Stratigraphy ranges from Lower Cambrian to Carboniferous, but it applies only to the Gondwanan realm. For other paleocontinents (Laurentia, Siberia) equivalent schemes still need to be worked out.