ON COVER —The top photo depicts a part of the great East African Rift Valley (overlooking the Rukwa Rift Basin) in southwestern Tanzania. See related article by Hilbert-Wolf et al. on p. 143 of this issue of the Bulletin. Photo by Eric Roberts. The bottom image is a detail of a Middle Jurassic hardground of pelagic swells in southeast Spain. It is showing a belemnite assemblage in a banded Fe–Mn crust. These are interpreted as regional unconformities related to major palaeogeographic changes at the south Iberian Palaeomargin. Fragmentation of the Western Tethys carbonate platform resulted in fault-controlled pelagic swells where these hardgrounds developed. See related article by Fernández-Ibáñez on p. 233 of this issue of the Bulletin. Image submitted by Fermín Fernández-Ibáñez.