Morphotectonic modeling of the Ibague strike-slip fault, Colombia. The Ibague Fault is a dextral strike-slip fault which runs in an ENE direction. It is by far the most notable feature of a transverse shear zone, which affects the Central Cordillera of the Colombian Andes. The fault, on leaving the east flank of the Cordillera, crosses an exten- sive alluvial plain of largely Pleistocene age, known as the Ibague Fan. It is along this stretch across the plain that the fault displays abun- dant morphologic features characteristic of strike-slip movement. The fault, as seen in remote sensing imagery and on aerial photos, appe- ars as one continuous trace, but closer inspection reveals that in fact it is in most places made up of sequences of synthetic dextral Riedel shears connected by pressure ridges varying greatly in size. A photogeologic survey followed by fieldwork permitted the selection of a sui- table site for the excavation of a trench for a paleoseismological study in a small pull-apart basin not affected by human activity. Preliminary inspection of the trench outcrop revealed a stratigraphic section recording eight seismic events during the Holocene.