Corrigendum to “Controls on strath terrace formation and evolution: The lower Guadiana River, Pulo do Lobo, Portugal” [Geomorphology 319 (2018) 62–77]

The lower Guadiana River carves a wide canyon in the Variscan metamorphic rocks of the SW Iberian Peninsula and presents an exceptionally homogeneous and well-preserved case of a strath terrace (ST) some 40 km long and 400 m wide. The rocky surface or strath shows different characteristics and development stages. Upstream, the lateral erosion level forms a flooded riverbed, or submerged strath, that gradually rises above the thalweg and develops into an active floodplain. Downstream, below the 15 m high Pulo do Lobo waterfall, the strath is incised by an inner canyon that forms a terrace on both sides. The inner channel increasingly widens and the ST loses its longitudinal continuity, yet remains prone to flooding during extraordinary magnitude floods. To assess the factors controlling the formation of this ST, we examined the roles of key drivers of ST formation: lithological hardness, tectonic structures and climate change, using cosmogenic data to create a chronologic context. The ST developed favoured by a monotonous succession of phyllites, as shown by Schmidt hammer resistance data, and interbedded more resistant quartz veins do not significantly alter its flat configuration. Variscan structures and measured joints determine the main orientation of the river and control the drainage network pattern. The intersection of the NS and NE-SW fractures promotes a wavy surface due to three-dimensional minor fold trains that act as discontinuities and play an important role in ST erosion through quarrying and plucking. However, we detected no evidence of ST deformation attributable to recent or Late Cenozoic tectonic activity.