Large-Scale Physiography of the Murzuq Basin Shelf during Hirnantian Ice-Sheet Final Retreat and Silurian Transgression

The Hirnantian glaciation strongly affected the lower Palaeozoic sedimentary succession of the Murzuq Basin (Libya). After final deglaciation, the remnant topography displays imprints of most of the ice-sheet retreat evolution. One large ice stream pathway, in the form of a wide erosional trough including surbordinate higher areas, has been recognized. Several ice-fronts and related proglacial fan-deltas are localized at basin scale. These architectural elements are closely associated with the position of the Ordovician reservoir relative to the Silurian “Hot Shale”.